共用题干
Avalanche and Its Safety
An avalanche is a sudden and rapid flow of snow,often mixed with air and water,down a mountainside .Avalanches are______(51)the biggest dangers in the mountains for both life and property.
All avalanches are caused by an over-burden of material,typically snowpack,that is too massive and unstable for the slope______(52)supports it. Determining the critical load,the amount of over-burden which is______(53)to cause an avalanche，______（54)a complex task involving the evaluation of a number of factors.
Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low ______(55)of avalanche .Snow does not______(56)significantly on steep slopes;also, snow does not______(57)easily on flat slopes.Human-triggered avalanches have the greatest incidence when the snow's angle of rest is______(58)35 and 45 degrees;the critical angle, the angle at which the human incidence of avalanches is greatest,is 38 degrees.The rule of thumb is:A slope that is______(59)enough to hold snow but steep enough to ski has the potential to generate an avalanche,regardless of the angle.Additionally,avalanche risk increases with ______(60);that is,the more a slope is disturbed by skiers,the more likely it is that an avalanche will occur.
Due to the complexity of the subject,winter travelling in the backcountry is never 100% safe .Good avalanche safety is a continuous______(61),including route selection and examination of the snowpack,weather______(62),and human factors.Several well-known good habits can also______(63)the risk .If local authorities issue avalanche risk reports,they should be considered and all warnings should be paid______(64)to.
Never follow in the tracks of others without your own evaluations;snow conditions are almost certain to have changed since they were made .Observe the terrain and note obvious avalanche paths where plants are ______(65)or damaged .Avoid travelling below others who might trigger an avalanche.
65._________
A: fresh
B: big
C:grown
D: missing
Avalanche and Its Safety
An avalanche is a sudden and rapid flow of snow,often mixed with air and water,down a mountainside .Avalanches are______(51)the biggest dangers in the mountains for both life and property.
All avalanches are caused by an over-burden of material,typically snowpack,that is too massive and unstable for the slope______(52)supports it. Determining the critical load,the amount of over-burden which is______(53)to cause an avalanche，______（54)a complex task involving the evaluation of a number of factors.
Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low ______(55)of avalanche .Snow does not______(56)significantly on steep slopes;also, snow does not______(57)easily on flat slopes.Human-triggered avalanches have the greatest incidence when the snow's angle of rest is______(58)35 and 45 degrees;the critical angle, the angle at which the human incidence of avalanches is greatest,is 38 degrees.The rule of thumb is:A slope that is______(59)enough to hold snow but steep enough to ski has the potential to generate an avalanche,regardless of the angle.Additionally,avalanche risk increases with ______(60);that is,the more a slope is disturbed by skiers,the more likely it is that an avalanche will occur.
Due to the complexity of the subject,winter travelling in the backcountry is never 100% safe .Good avalanche safety is a continuous______(61),including route selection and examination of the snowpack,weather______(62),and human factors.Several well-known good habits can also______(63)the risk .If local authorities issue avalanche risk reports,they should be considered and all warnings should be paid______(64)to.
Never follow in the tracks of others without your own evaluations;snow conditions are almost certain to have changed since they were made .Observe the terrain and note obvious avalanche paths where plants are ______(65)or damaged .Avoid travelling below others who might trigger an avalanche.
65._________
A: fresh
B: big
C:grown
D: missing
共用题干
Black Holes
1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists
have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer
burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,
hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.
2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these
explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough
(should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact
every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends
up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S
only a fraction of an inch!
3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember
that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large
star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not
change because the newly formed black hole contains exactly the same amount of mass as when it was a star,
only this time its mass is totally contracted that it can end up as no bigger than a state.
4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of
relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black
holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But
astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes
might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger
process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black
holes as helpful in learning how galaxies began to form.
Albert Einstein's theory of relativity helps to prove__________.
A:the existence of black holes
B:the creation of new entities
C:the same amount of mass
D:an fraction of an inch
E:a fraction of an inch
F:the tiniest particle
Black Holes
1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists
have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer
burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,
hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.
2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these
explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough
(should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact
every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends
up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S
only a fraction of an inch!
3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember
that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large
star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not
change because the newly formed black hole contains exactly the same amount of mass as when it was a star,
only this time its mass is totally contracted that it can end up as no bigger than a state.
4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of
relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black
holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But
astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes
might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger
process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black
holes as helpful in learning how galaxies began to form.
Albert Einstein's theory of relativity helps to prove__________.
A:the existence of black holes
B:the creation of new entities
C:the same amount of mass
D:an fraction of an inch
E:a fraction of an inch
F:the tiniest particle
共用题干
The Smog（烟雾）
For over a month,lndonesia was in crisis.Forest fires raged out of control as the
country suffered its worst drought for 50 years.Smoke from the fires mixed with sunlight and
hot dry air to form a cloud of smog.This pollution quickly spread and within days it was
hanging over neighbouring countries including Malaysia,Singapore and Thailand.
When the smoke combined with pollution from factories and cars,it soon became
poisonous（有毒的）.Dangerous amounts of CO became trapped under the smog and
pollution levels rose. People wheezed（喘息）and coughed as they left the house and their
eyes watered immediately.
The smog made it impossible to see across streets and whole cities disappeared as
grey soot（烟灰）covered everything. In some areas, water was hosed（用胶管浇）from
high-rise city buildings to try and break up the smog.
Finally,heavy rains,which came in November,put out the fires and cleared the air.
But the environmental costs and health problems will remain.Many people from South-
Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes（汽车
排放的废气）and factory pollution. Breathing problems could well increase and many non-
sufferers may have difficulties for the first time.Wildlife has suffered too.In lowland forests,elephants,deer,and tigers have been driven out of their homes by smog.
But smog is not just an Asian problem.In fact,the word was first used in London in
1905 to describe the mixture of smoke and thick fog.Fog often hung over the capital.
Sometimes the smog was so thick and poisonous that people were killed by breathing
problems or in accidents.About 4, 000 Londoners died within five days as a result of thick
smog in 1952.
The word"smog"first appeared in 1952.
A:Right
B:Wrong
C:Not mentioned
The Smog（烟雾）
For over a month,lndonesia was in crisis.Forest fires raged out of control as the
country suffered its worst drought for 50 years.Smoke from the fires mixed with sunlight and
hot dry air to form a cloud of smog.This pollution quickly spread and within days it was
hanging over neighbouring countries including Malaysia,Singapore and Thailand.
When the smoke combined with pollution from factories and cars,it soon became
poisonous（有毒的）.Dangerous amounts of CO became trapped under the smog and
pollution levels rose. People wheezed（喘息）and coughed as they left the house and their
eyes watered immediately.
The smog made it impossible to see across streets and whole cities disappeared as
grey soot（烟灰）covered everything. In some areas, water was hosed（用胶管浇）from
high-rise city buildings to try and break up the smog.
Finally,heavy rains,which came in November,put out the fires and cleared the air.
But the environmental costs and health problems will remain.Many people from South-
Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes（汽车
排放的废气）and factory pollution. Breathing problems could well increase and many non-
sufferers may have difficulties for the first time.Wildlife has suffered too.In lowland forests,elephants,deer,and tigers have been driven out of their homes by smog.
But smog is not just an Asian problem.In fact,the word was first used in London in
1905 to describe the mixture of smoke and thick fog.Fog often hung over the capital.
Sometimes the smog was so thick and poisonous that people were killed by breathing
problems or in accidents.About 4, 000 Londoners died within five days as a result of thick
smog in 1952.
The word"smog"first appeared in 1952.
A:Right
B:Wrong
C:Not mentioned
共用题干
Germs（细菌）on Banknotes
People in different countries use different types of money:yuan in China,pesos in Mexico,pounds in the United Kingdom,dollars in the United States,Australia and New Zeal-and. They may use different currencies,but these countries,and probably all countries,still have one thing in______(1):germs on the banknotes.
Scientists have been studying the germs on money for well over 100 years. At the turn of the 20th______(2),some researchers began to suspect that germs living on money could spread disease.
Most studies of germy money have looked at the germs on the currency______(3)one country. In a new study,Frank Vriesekoop and other researchers compared the germ populations found on bills of different______(4).
Vriesekoop is a microbiologist at the University of Ballarat in Australia. He led the stud-y,which compared the germ populations found on money______(5)from 10 nations. The scientists studied 1,280 banknotes in total;all came from places where people buy food,like supermarkets,street vendors and cafes,______(6)those businesses often rely on cash.
Overall,the Australian dollars hosted the fewest live bacteria一no more than 10 per square centimeter. Chinese yuan had the______(7）about 100 per square centimeter. Most of the germs on money probably would not cause harm.
What we call“paper money”_________(8)isn't made from paper. The U. S. dollar,for ex- ample,is printed on fabric that is mostly cotton. Different countries may use different______(9)to print their money. Some of the currencies studied by Vriesekoop and his team,such as the American dollar,were made from cotton. Others were made from polymers.
The three______(10)with the lowest numbers of bacteria were all printed on poly-mers. They included the Australian dollar,the New Zealand dollar and some Mexican pesos.
The______(11)currencies were printed on fabric made mostly of cotton. Fewer germs lived on the polymer notes. This______(12)suggests that germs have a harder time staying alive on polymer surfaces. Scientists need to do more studies to understand______(13)germs live on, mon-ey—and whether or not we need to be concerned. Vriesekoop is now starting a study that will______(14)the amounts of time bacteria can stay alive on different types of bills.
Whatever Vriesekoop finds,the fact remains:Paper money______(15)germs. We should wash our hands after touching it;After all,you never know where your money's been. Or what's living on it.
15._________
A: avoids
B: kills
C: carries
D: selects
Germs（细菌）on Banknotes
People in different countries use different types of money:yuan in China,pesos in Mexico,pounds in the United Kingdom,dollars in the United States,Australia and New Zeal-and. They may use different currencies,but these countries,and probably all countries,still have one thing in______(1):germs on the banknotes.
Scientists have been studying the germs on money for well over 100 years. At the turn of the 20th______(2),some researchers began to suspect that germs living on money could spread disease.
Most studies of germy money have looked at the germs on the currency______(3)one country. In a new study,Frank Vriesekoop and other researchers compared the germ populations found on bills of different______(4).
Vriesekoop is a microbiologist at the University of Ballarat in Australia. He led the stud-y,which compared the germ populations found on money______(5)from 10 nations. The scientists studied 1,280 banknotes in total;all came from places where people buy food,like supermarkets,street vendors and cafes,______(6)those businesses often rely on cash.
Overall,the Australian dollars hosted the fewest live bacteria一no more than 10 per square centimeter. Chinese yuan had the______(7）about 100 per square centimeter. Most of the germs on money probably would not cause harm.
What we call“paper money”_________(8)isn't made from paper. The U. S. dollar,for ex- ample,is printed on fabric that is mostly cotton. Different countries may use different______(9)to print their money. Some of the currencies studied by Vriesekoop and his team,such as the American dollar,were made from cotton. Others were made from polymers.
The three______(10)with the lowest numbers of bacteria were all printed on poly-mers. They included the Australian dollar,the New Zealand dollar and some Mexican pesos.
The______(11)currencies were printed on fabric made mostly of cotton. Fewer germs lived on the polymer notes. This______(12)suggests that germs have a harder time staying alive on polymer surfaces. Scientists need to do more studies to understand______(13)germs live on, mon-ey—and whether or not we need to be concerned. Vriesekoop is now starting a study that will______(14)the amounts of time bacteria can stay alive on different types of bills.
Whatever Vriesekoop finds,the fact remains:Paper money______(15)germs. We should wash our hands after touching it;After all,you never know where your money's been. Or what's living on it.
15._________
A: avoids
B: kills
C: carries
D: selects
Housewives who do not go out to work often feel they are not working to their full ability．
A:capacity
B:strength
C:length
D:possibility
A:capacity
B:strength
C:length
D:possibility
Your teacher will take your illness into account when marking your exams.
A:calculation
B:computation
C:consideration
D:assessment
A:calculation
B:computation
C:consideration
D:assessment
共用题干
Water一the Issue of This Century
The world is running short of freshwater. Populations are growing bigger and thirstier （渴的）,with the result that freshwater is becoming increasingly scarce（缺乏）.Half the world's wetlands have disappeared during the last century,while estimates suggest that wa- ter use will rise by 50% in the next 30 years.
The World Bank report estimates that as much as half of the world's population,concentrated in Africa,the Middle East and south Asia,will face“severe water shortages”by 2025.Local water conflicts and the loss of freshwater ecosystems appear large in some re- gions.
A similar picture emerges from the globe's salt water regions. Three-quarters of the world's people may live within 100km of the sea in 2025,putting even more pressure on stretched coastal ecosystems. Two thirds of fisheries（渔业）are exploited at or beyond their sustainable limits, and half the world's coral reefs（珊瑚礁）may perish in 100 years. Almost 60% of coral reefs and 34% of fish species are at risk from human activities,the Bank says.
The report concludes that there is ample evidence to justify immediate and coordinated action to safeguard supplies and use water more efficiently.
Fresh water consumption is rising quickly,and the availability of water in some regions is likely to become one of the most pressing issues of the 21st century.
A third of the world's popu1ation一around two billion people一live in countries that are experiencing moderate to high water shortages.That proportion could rise to half or more in the next 30 years unless institutions（制度）change to ensure better conservation and alloca- tion of water.
China is one country where the portents（征兆）are gloomy. The most waterstressed country in East Asia,China is exploiting 44%of its usable water,a figure projected to rise to6O%by 2020.Primary withdrawal of water of more than 60%is widely considered by water experts to exceed the environmental carrying capacity of a river basin system. Although
China's total use appears still to be reasonable,it has several basins that are severely stressed environmentally.
Withdrawals exceed environmental limits in Afghanistan and Pakistan,and will exceed them in India by 2020.In the Middle East and North Africa,only Morocco has unexploited water resources.The rest have exceeded environmental limits and many are mining aquifers （蓄水层）一bodies of water-bearing rock一the report says.
It is estimated that water use will rise by 50% in the next 30 years.
A: Right
B: Wrong
C: Not mentioned
Water一the Issue of This Century
The world is running short of freshwater. Populations are growing bigger and thirstier （渴的）,with the result that freshwater is becoming increasingly scarce（缺乏）.Half the world's wetlands have disappeared during the last century,while estimates suggest that wa- ter use will rise by 50% in the next 30 years.
The World Bank report estimates that as much as half of the world's population,concentrated in Africa,the Middle East and south Asia,will face“severe water shortages”by 2025.Local water conflicts and the loss of freshwater ecosystems appear large in some re- gions.
A similar picture emerges from the globe's salt water regions. Three-quarters of the world's people may live within 100km of the sea in 2025,putting even more pressure on stretched coastal ecosystems. Two thirds of fisheries（渔业）are exploited at or beyond their sustainable limits, and half the world's coral reefs（珊瑚礁）may perish in 100 years. Almost 60% of coral reefs and 34% of fish species are at risk from human activities,the Bank says.
The report concludes that there is ample evidence to justify immediate and coordinated action to safeguard supplies and use water more efficiently.
Fresh water consumption is rising quickly,and the availability of water in some regions is likely to become one of the most pressing issues of the 21st century.
A third of the world's popu1ation一around two billion people一live in countries that are experiencing moderate to high water shortages.That proportion could rise to half or more in the next 30 years unless institutions（制度）change to ensure better conservation and alloca- tion of water.
China is one country where the portents（征兆）are gloomy. The most waterstressed country in East Asia,China is exploiting 44%of its usable water,a figure projected to rise to6O%by 2020.Primary withdrawal of water of more than 60%is widely considered by water experts to exceed the environmental carrying capacity of a river basin system. Although
China's total use appears still to be reasonable,it has several basins that are severely stressed environmentally.
Withdrawals exceed environmental limits in Afghanistan and Pakistan,and will exceed them in India by 2020.In the Middle East and North Africa,only Morocco has unexploited water resources.The rest have exceeded environmental limits and many are mining aquifers （蓄水层）一bodies of water-bearing rock一the report says.
It is estimated that water use will rise by 50% in the next 30 years.
A: Right
B: Wrong
C: Not mentioned
共用题干
Electromagnetic Energy
1 White light seems to be a combination of all colors.The energy that comes from a source of light is
not limited to the kind of energy you can see.Heat is given off by a flame or an electric light.On a cloudy
day it is possible to get a sunburn even though you feel cool.Visible light and the kind of energy that produce
warmth and sunburn are examples of electromagnetic energy.
2 The sun is 93 million miles away from the earth.Yet we can use energy from the sun because elec-
tromagnetic energy travels through space.
3 Many other kinds of energy are also types of electromagnetic energy.Radio,television,and radar signals
travel from transmitters to receivers as low-energy electromagnetic waves. Infrared（红外线的）radiation is an
electromagnetic wave.When it is absorbed by matter,heat is produced.Waves of infrared and visible light
have more energy than waves of radio , television , or radar. Ultraviolet rays（紫外线）and X-rays are electro-
magnetic waves with even greater amounts of energy.Infrared radiation is used in cooking food and heating
buildings.Sunlight and electric lights are part of our requirements for normal living. Ultraviolet radiation is
useful in killing certain disease organisms.X-rays and gamma rays have so much energy that they travel right
through solid objects.They can be used to detect and treat cancer. X-rays are used in industry to find hidden
cracks in metal,and in medicine to reveal broken bones.
4 Usually we use electricity to generate electromagnetic energy.The source of most of our energy is the
sun.Heat from the sun causes water to evaporate.When the water falls to the earth as rain,some of it is
trapped behind dams and then used to operate electric generators.Other generators are powered by coal,but
the energy stored in coal came from the sun,too.
5 Until recently,the source of the tremendous amount of energy given off by the sun was a puzzle.If
the.sun depended on chemical reactions,it would have used up all its energy long ago.Experiments with
electromagnetic radiation led to the theory that mass can be converted into energy.About forty years after the
theory was proposed , nuclear energy was harnessed（利用）by man. Chemical energy comes from electron
（电子）rearrangement. Nuclear energy comes from a change in the nucleus of an atom. Compared with chemi-
cal reactions,nuclear reactions release millions of times more energy per pound of fuel.We now believe that
the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium（氦）.
6 Nuclear energy is beginning to compete with coal as an economical source of power to generate elec-
tncity.It is also being used to operate engines in large ships.Scientists continue to seek new and better
methods of obtaining and using energy.
When electron rearrangement takes place,_____________.
A:electromagnetic energy
B:electromagnetic energy travels through space
C:came from the sun
D:when a change in the nucleus of an atom takes place
E:when the sunrays are fierce
F:chemical energy is generated
Electromagnetic Energy
1 White light seems to be a combination of all colors.The energy that comes from a source of light is
not limited to the kind of energy you can see.Heat is given off by a flame or an electric light.On a cloudy
day it is possible to get a sunburn even though you feel cool.Visible light and the kind of energy that produce
warmth and sunburn are examples of electromagnetic energy.
2 The sun is 93 million miles away from the earth.Yet we can use energy from the sun because elec-
tromagnetic energy travels through space.
3 Many other kinds of energy are also types of electromagnetic energy.Radio,television,and radar signals
travel from transmitters to receivers as low-energy electromagnetic waves. Infrared（红外线的）radiation is an
electromagnetic wave.When it is absorbed by matter,heat is produced.Waves of infrared and visible light
have more energy than waves of radio , television , or radar. Ultraviolet rays（紫外线）and X-rays are electro-
magnetic waves with even greater amounts of energy.Infrared radiation is used in cooking food and heating
buildings.Sunlight and electric lights are part of our requirements for normal living. Ultraviolet radiation is
useful in killing certain disease organisms.X-rays and gamma rays have so much energy that they travel right
through solid objects.They can be used to detect and treat cancer. X-rays are used in industry to find hidden
cracks in metal,and in medicine to reveal broken bones.
4 Usually we use electricity to generate electromagnetic energy.The source of most of our energy is the
sun.Heat from the sun causes water to evaporate.When the water falls to the earth as rain,some of it is
trapped behind dams and then used to operate electric generators.Other generators are powered by coal,but
the energy stored in coal came from the sun,too.
5 Until recently,the source of the tremendous amount of energy given off by the sun was a puzzle.If
the.sun depended on chemical reactions,it would have used up all its energy long ago.Experiments with
electromagnetic radiation led to the theory that mass can be converted into energy.About forty years after the
theory was proposed , nuclear energy was harnessed（利用）by man. Chemical energy comes from electron
（电子）rearrangement. Nuclear energy comes from a change in the nucleus of an atom. Compared with chemi-
cal reactions,nuclear reactions release millions of times more energy per pound of fuel.We now believe that
the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium（氦）.
6 Nuclear energy is beginning to compete with coal as an economical source of power to generate elec-
tncity.It is also being used to operate engines in large ships.Scientists continue to seek new and better
methods of obtaining and using energy.
When electron rearrangement takes place,_____________.
A:electromagnetic energy
B:electromagnetic energy travels through space
C:came from the sun
D:when a change in the nucleus of an atom takes place
E:when the sunrays are fierce
F:chemical energy is generated
共用题干
New Changes in American Life
Once it was possible to define male and female roles easily by the division of labor. Men worked outside the home and earned the income to support their families,while women cooked the meals and took care of the home and the children.______(46)But by the middle of this centu-ry,men's and women's roles were becoming less firmly fixed.
In the 1950s,economic and social success was the goal of the typical American.But in the 1960s a new force developed called the counterculture.______(47)The counterculture presented men and women with new role choices.Taking more interest in childcare,men began to share child-raising tasks with their wives.In fact,some young men and women moved to communal homes or farms where the economic and childcare responsibilities were shared equally by both sexes.______(48)Some young men refused to be drafted as soldiers to fight in the war in Vietnam.
In terms of numbers,the counterculture was not a very large group of people._______(49) Working men of all classes began to change their economic and social patterns.Industrial workers and business executives alike cut down on"overtime"work so that they could spend more leisure time with their families.Some doctors,lawyers,and teachers turned away from high paying situations to practice their professions in poorer neighborhoods.
In the 1970s,the feminist movement,or women's liberation,produced additional economic and social changes.Women of all ages and at all levels of society were entering the work force in greater numbers.______(50)But some women began to enter traditionally male occupations: police work,banking,dentistry,and construction work.Women were asking for equal work,and equal opportunities for promotion.
Today the experts generally agree that important changes are taking place in the roles of men and women .Naturally,there are difficulties in adjusting to these transformations.
_______(49)
A: In addition,many Americans did not value the traditional male role of soldier.
B: Most of them still took traditional women's jobs as public school teaching,nursing,and secretarial work.
C: These roles were firmly fixed for most people,and there was not much opportunity for women to exchange their roles.
D: But its influence spread to many parts of American society.
E: The people involved in this movement did not value the middle-class American goals.
F: A great many jobs that used to belong to men are now taken by women.
New Changes in American Life
Once it was possible to define male and female roles easily by the division of labor. Men worked outside the home and earned the income to support their families,while women cooked the meals and took care of the home and the children.______(46)But by the middle of this centu-ry,men's and women's roles were becoming less firmly fixed.
In the 1950s,economic and social success was the goal of the typical American.But in the 1960s a new force developed called the counterculture.______(47)The counterculture presented men and women with new role choices.Taking more interest in childcare,men began to share child-raising tasks with their wives.In fact,some young men and women moved to communal homes or farms where the economic and childcare responsibilities were shared equally by both sexes.______(48)Some young men refused to be drafted as soldiers to fight in the war in Vietnam.
In terms of numbers,the counterculture was not a very large group of people._______(49) Working men of all classes began to change their economic and social patterns.Industrial workers and business executives alike cut down on"overtime"work so that they could spend more leisure time with their families.Some doctors,lawyers,and teachers turned away from high paying situations to practice their professions in poorer neighborhoods.
In the 1970s,the feminist movement,or women's liberation,produced additional economic and social changes.Women of all ages and at all levels of society were entering the work force in greater numbers.______(50)But some women began to enter traditionally male occupations: police work,banking,dentistry,and construction work.Women were asking for equal work,and equal opportunities for promotion.
Today the experts generally agree that important changes are taking place in the roles of men and women .Naturally,there are difficulties in adjusting to these transformations.
_______(49)
A: In addition,many Americans did not value the traditional male role of soldier.
B: Most of them still took traditional women's jobs as public school teaching,nursing,and secretarial work.
C: These roles were firmly fixed for most people,and there was not much opportunity for women to exchange their roles.
D: But its influence spread to many parts of American society.
E: The people involved in this movement did not value the middle-class American goals.
F: A great many jobs that used to belong to men are now taken by women.
共用题干
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.
According to the passage,"weight"should be understood in the sense that
A:it is fixed if it is outside the earth's gravitational puli
B:it decreases four times when it is 4,000 miles from the earth's center
C:it varies with the change of the gravitational attraction between two objects
D:things increase in amount as they are closer to the earth's surface
Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.
According to the passage,"weight"should be understood in the sense that
A:it is fixed if it is outside the earth's gravitational puli
B:it decreases four times when it is 4,000 miles from the earth's center
C:it varies with the change of the gravitational attraction between two objects
D:things increase in amount as they are closer to the earth's surface
共用题干
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Paragraph 4 ______________
A:Popularity and Use of Natural Gas
B:Natural Gas Reserves and Supply
C:Natural Gas Prices
D:Clean Fuel of Choice
E:Disadvantages of Natural Gas
F:Natural Gas Consumption
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Paragraph 4 ______________
A:Popularity and Use of Natural Gas
B:Natural Gas Reserves and Supply
C:Natural Gas Prices
D:Clean Fuel of Choice
E:Disadvantages of Natural Gas
F:Natural Gas Consumption
共用题干
The Arctic Ice is Thawing
Father Christmas may have to move his"workshop"from the North Pole because global warming is thawing the ice beneath his feet and his reindeers'feet as well.His"workshop"is in dire straits.The"platform"for the "workshop"is melting,said Stefan Norris of the World Wildlife Fund environmental group's Arctic Program.
An eight-nation report by 250 scientists published recently predicted the Arctic Ocean could be ice-free in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere,mainly from burning fossil fuels in cars or factories.The North Pole is getting more and more uninhabitable to Father Christmas.______(46)Young people learn that Father Christmas'"workshop"produces millions of gifts delivered
by him on a flying,reindeer-drawn sleigh（雪橇）.Hollywood movies like"The Polar Express" tried to make viewers believe that Father Christmas lives at the North Pole.___＿_(47)
The"Fortress of Solitude"is near the North Pole that could be under threat in a warmer world.Alan Boldt, spokesman of the Danish Ministry of Science,suggested ways to rescue Father Christmas.______(48) Another alternative,he argued,would be building some electrical facilities to ensure the ice stays on the North
Pole for him."This should be a subject for the United Nations,"he said."Denmark could build windmills to provide Father Christmas with power."Denmark says Father Christmas'real home is Greenland,which will help, Denmark thinks,to strengthen its position in claiming the sovereignty over the Pole.______(49) "Doesn't he already speak Danish?"Boldt said frostily when asked if Father Christmas would be forced to learn Danish if Denmark won international recognition of its claim to the Pole.Last month's Arctic report said the region is warming twice as fast as the rest of the globe,partly because dark ground or water,once uncovered,soaks up more heat than ice or snow.Finland has been most favored by Father Christmas and it has about 500,000 tourists a year to visit its Christmas center in Rovaniemi in Lapland.______(50)
______(47)
A:However,Nordic nations all reject it by claiming that their countries are his home.
B:Therefore the North Pole is the most attractive place in the world.
C:If Denmark's claim were accepted internationally,it would have the legal right to search for oil and gas at the North Pole.
D:One of them would be building a giant floating ice rink for the workshop if the Pole thaws.
E:Maybe Father Christmas has already moved to Rovaniemi.
F:He may have to move from the North Pole within our children's lifetimes.
The Arctic Ice is Thawing
Father Christmas may have to move his"workshop"from the North Pole because global warming is thawing the ice beneath his feet and his reindeers'feet as well.His"workshop"is in dire straits.The"platform"for the "workshop"is melting,said Stefan Norris of the World Wildlife Fund environmental group's Arctic Program.
An eight-nation report by 250 scientists published recently predicted the Arctic Ocean could be ice-free in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere,mainly from burning fossil fuels in cars or factories.The North Pole is getting more and more uninhabitable to Father Christmas.______(46)Young people learn that Father Christmas'"workshop"produces millions of gifts delivered
by him on a flying,reindeer-drawn sleigh（雪橇）.Hollywood movies like"The Polar Express" tried to make viewers believe that Father Christmas lives at the North Pole.___＿_(47)
The"Fortress of Solitude"is near the North Pole that could be under threat in a warmer world.Alan Boldt, spokesman of the Danish Ministry of Science,suggested ways to rescue Father Christmas.______(48) Another alternative,he argued,would be building some electrical facilities to ensure the ice stays on the North
Pole for him."This should be a subject for the United Nations,"he said."Denmark could build windmills to provide Father Christmas with power."Denmark says Father Christmas'real home is Greenland,which will help, Denmark thinks,to strengthen its position in claiming the sovereignty over the Pole.______(49) "Doesn't he already speak Danish?"Boldt said frostily when asked if Father Christmas would be forced to learn Danish if Denmark won international recognition of its claim to the Pole.Last month's Arctic report said the region is warming twice as fast as the rest of the globe,partly because dark ground or water,once uncovered,soaks up more heat than ice or snow.Finland has been most favored by Father Christmas and it has about 500,000 tourists a year to visit its Christmas center in Rovaniemi in Lapland.______(50)
______(47)
A:However,Nordic nations all reject it by claiming that their countries are his home.
B:Therefore the North Pole is the most attractive place in the world.
C:If Denmark's claim were accepted internationally,it would have the legal right to search for oil and gas at the North Pole.
D:One of them would be building a giant floating ice rink for the workshop if the Pole thaws.
E:Maybe Father Christmas has already moved to Rovaniemi.
F:He may have to move from the North Pole within our children's lifetimes.
共用题干
Genetically Modified Food
Ever since they were first put on the market in the early 1990s,genetically modified(GM，转基因）foods have been increasingly developed and marketed in many countries in the world, mainly on the basis of their promise to end the worldwide food crisis.______(46)Even if it would,is it the best solution?
Despite what it promises,GM technology actually has not increased the production potential （潜力）of any crop.______(47)For instance,a report that analyses nearly two decades of research on major GM food shows that GM engineering has failed to significantly increase US crop production.
______(48)While GM seeds are expensive,GM companies tell farmers that they will make good profits by saving money on pesticides（杀虫剂）.On the contrary, US government data show that GM crops in the US have produced an overall increase in pesticide use compared to traditional crops."The promise was that you could use less chemicals and boost production.But neither is true,"said Bill Christison,President of the US National Family Farm Coalition.
At the same time,the authors of the book World Hunger:Twelve Myths argue that there actually is more than enough food in the world and that the hunger crisis is not caused by production. ______(49)These indeed deserve our efforts and money. Meanwhile,the rise in food prices results from the increased use of crops for fuel rather than food shortage,according to a 2008 World Bank report.
______(50)Another World Bank report concluded that GM crops have little to offer to the challenges of worldwide poverty and hunger,because better ways out are available,among which "green"farming is supposed to be the first choice.
_______（49）
A:Problems come from food distribution and politics.
B:But can GM technology solve world hunger problems?
C:In fact,studies show that the most widely grown GM crop has suffered reduced productivity.
D:As a matter of fact,scientists see better ways to feed the world.
E:Something else,however,has been on the rise.
F: GM has many benefits when it was used at the beginning.
Genetically Modified Food
Ever since they were first put on the market in the early 1990s,genetically modified(GM，转基因）foods have been increasingly developed and marketed in many countries in the world, mainly on the basis of their promise to end the worldwide food crisis.______(46)Even if it would,is it the best solution?
Despite what it promises,GM technology actually has not increased the production potential （潜力）of any crop.______(47)For instance,a report that analyses nearly two decades of research on major GM food shows that GM engineering has failed to significantly increase US crop production.
______(48)While GM seeds are expensive,GM companies tell farmers that they will make good profits by saving money on pesticides（杀虫剂）.On the contrary, US government data show that GM crops in the US have produced an overall increase in pesticide use compared to traditional crops."The promise was that you could use less chemicals and boost production.But neither is true,"said Bill Christison,President of the US National Family Farm Coalition.
At the same time,the authors of the book World Hunger:Twelve Myths argue that there actually is more than enough food in the world and that the hunger crisis is not caused by production. ______(49)These indeed deserve our efforts and money. Meanwhile,the rise in food prices results from the increased use of crops for fuel rather than food shortage,according to a 2008 World Bank report.
______(50)Another World Bank report concluded that GM crops have little to offer to the challenges of worldwide poverty and hunger,because better ways out are available,among which "green"farming is supposed to be the first choice.
_______（49）
A:Problems come from food distribution and politics.
B:But can GM technology solve world hunger problems?
C:In fact,studies show that the most widely grown GM crop has suffered reduced productivity.
D:As a matter of fact,scientists see better ways to feed the world.
E:Something else,however,has been on the rise.
F: GM has many benefits when it was used at the beginning.
共用题干
The Differences Among Various Types of Adoption
In the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster（收养的）children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.
Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish（放弃）their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.
Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.
International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.
Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them.
_________(64)
A:procedure
B:profile
C:process
D:project
The Differences Among Various Types of Adoption
In the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster（收养的）children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.
Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish（放弃）their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.
Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.
International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.
Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them.
_________(64)
A:procedure
B:profile
C:process
D:project
Nothing would induce me to vote for him again.
A:teach
B: help
C: attract
D: discourage
A:teach
B: help
C: attract
D: discourage