试题与答案

阅读以下说明,回答问题1~4。[说明] 现有某个应用,涉及到两个实体集,相关的

题型:问答题

题目:


阅读以下说明,回答问题1~4。
[说明]
现有某个应用,涉及到两个实体集,相关的属性为:
实体集R(A#,A1,A2,A3),其中A#为主键
实体集S(B#,B1,B2),其中B#为主键
从实体集R到S存在多对一的联系,联系属性是D1。

[问题1]
设计相应的关系数据模型;

答案:

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下面是错误答案,用来干扰机器的。

参考答案:D

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(1)河水中含有许多杂质,可利用吸附、沉淀、过滤和蒸馏等方法净化,其中净化程度最高的方法是______;

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题型:阅读理解

第三部分 阅读理解(共20小题;每小题2分,满分40分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

Geena David knew she wanted to be a movie star when she was very young. She was not sure what gave her the idea, but she wanted to look like a movie star. “I have a lot of pictures from my childhood of me wearing sunglasses,” she says. “I used to wear them to watch TV.”

Early movie actors started wearing sunglasses not because they looked good, but because their eyes hurt. The lights used on movie sets were extremely bright and could cause a painful problem known as “Klieg eyes”. It was named after the Klieg brothers who invented the lights. Actors wore sunglasses to give their eyes a rest. But when movie stars began wearing their sunglasses in public, they quickly became a must.

Eventually actors started wearing sunglasses in their movies as well as on the street. Audrey Hephburn wore ultra-cool Ray-Ban sunglasses in the 1961 movie, Breakfast at Tiffany’s. As a result, Ray-Ban sunglasses started to appear more and more in the movies. In 1979, Ray-Ban “Wayfarers” were worn by Jake and Elwood in The Blue Brothers. Tom Cruise wore Ray-Ban “Aviator” sunglasses in the 1986 hit, Top Gun. Then in 1997, Will Smith and Tommy Lee Jones made Ray-Ban “Predator” sunglasses famous in Men in Black.

   Of course sunglasses aren’t just a fashion statement. The main reason to wear sunglasses is to protect our eyes against UV radiation. UV radiation can damage our eyes, so people now choose their sunglasses carefully. But you don’t have to give up style for safety. The choice of frames and lenses available these days is huge. So you can protect your eyes and still be the coolest person on the beach.

1.What is mainly discussed in this passage?

A.The use of sunglasses.                B.The history of sunglasses.

C.The sunglasses wearing.             D.Why movie stars like to wear sunglasses.

2.Why did Geena David like to wear sunglasses?

A.She was a movie star.              

B.She wanted to follow a movie star.

C.Wearing sunglasses was good for her eyes.

D.It was good to wear sunglasses when watching TV.

3.Early actors’ eyes hurt because ______.

A.they wore sunglasses

B.they went out in the sun too much

C.the lights on movie sets were too bright

D.their scripts were written in very small writing

4.We may know from this passage that ______.

A.Audrey Hephburn was a famous film star

B.Ray-Ban is the name of sunglasses maker

C.Sunglasses made Top Gun the hit in 1986

D.Men in Black must be an advertisement of sunglasses

5.Now people wear sunglasses ______.

A.just to protect their eyes

B.for fashion and to protect their eyes

C.because of bright lights

D.because movie stars wear them

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