问题 单项选择题

在数据库设计中,将E-R图转换成关系数据模型的过程属于

A.需求分析阶段

B.概念设计阶段

C.逻辑设计阶段

D.物理设计阶段

答案

参考答案:C

解析:数据库的逻辑设计分为:①将概念模型转换成一般的数据模型;②将一般的数据模型转换为特定的数据库管理系统所支持的数据模型。把概念模型转换成关系数据模型就是把E-R图转换成一组关系模式。

阅读理解

Mike found a job in a bookstore after he finished middle school. He wouldn’t do anything but wanted to get rich.

It was a cold morning. It snowed and there was thin ice on the streets. Few people went to buy books and the young man had nothing to do. He hated to read, so he watched the traffic. Suddenly he saw a bag fall off a truck and it landed by the other side of the street.

“It is full of expensive things.” Mike said to himself. “I have to get it right now, or others will take it away.”

He went out of the bookstore and ran across the street. A driver saw him and began to whistle (鸣笛), but he didn’t hear it and went on running. The man drove to the side, hit a big tree and hurt himself in the accident. Two weeks later, Mike was taken to the court (法庭). A judge asked if he heard the whistle when he was running across the street. He said that something was wrong with his ears and he could hear nothing.

“But you heard me this time,” said the judge.

“Oh, I’m sorry. Now I can hear with one ear.”

“Cover (盖住) the ear with your hand and listen to me with your deaf (聋的) one. Well, can you hear me?”

“No, I can’t , sir.”

“You told a lie. There is nothing wrong with either of your ears,” the judge said.

小题1:Mike found a job as a _____________ when he left school.

A.driver

B.judge

C.policeman

D.bookseller小题2:One day he saw __________ in the street.

A.an accident

B.a thief

C.a lost bag

D.a lot of money小题3:The traffic accident happened because _____________.

A.Mike was running to the street

B.the driver was deaf and couldn’t hear anything

C.the car hit the bag in the middle of the street

D.the driver wanted to pick up the bag小题4:Which of the following statements is NOT true?

A.Mike didn’t do well in his work.

B.The judge believed Mike’s words.

C.Mike told a lie.

D.The car hit a tree beside the street.

单项选择题