During the systems analysis phase ，you must decide how data will be organized，stored，and managed. A（ ）is a framework for organizing，storing，and managing data. Each file or table contains data about people，places，things，or events. One of the potential problems existing in a file processing environment is（ ）,which means that data common to two or more information systems is stored in several places.

In a DBMS，the linked tables form a unified data structure that greatly improves dataquality and access. A(n)（ ）is a model that shows the logical relationships and interaction among system entities . It provides an overall view of the system and a blueprint for creating the physical data structures.（ ）is the process of creating table designs by assigning specific fields or attributes to each table in the database. A table design specifies the fields and identifies the primary key in a particular table or file. The three normal forms constitute a progression in which（ ）represents the best design. Most business-related databases must be designed in that form.

A.data entity B.data structure C.file collection D.data definition问题2： A.data integrity B.the rigid data structure C.data redundancy D.the many-to-many relationship问题3： A.entity-relationship diagram B.data dictionary C.database schema D.physical database model问题4： A.Normalization B.Replication C.Partitioning D.Optimization问题5： A.standard notation form B.first normal form C.second normal form D.third normal form