问题 单项选择题 A1/A2型题

在X线束中,中心线以外的射线都称为()

A.散射线

B.电子线

C.中心线

D.阳极线

E.斜射线

答案

参考答案:A

解析:在X线束中,中心线以外的射线都称为散射线。

阅读理解

阅读理解。

     The private automobile (私家车) has long played an important role in the United States. In fact, it has

become a necessary and important part of the American way of life. In 1986, sixty-nine percent of American

families owned at least one car, and thirty-eight percent had more than one. By giving workers rapid

transportation, the automobile has freed them from having to live near their place of work. This has encouraged

the growth of the cities, but it has also led to traffic problems.

     For farm families the automobile is very helpful. It has made it possible for them to travel to town very

often for business and for pleasure, and also to transport their children to distant schools.

     Family life has been affected (影响) in various ways, The car helps to keep families together when it is

used for picnics, outings, and other shared experiences. However, when teenage children have the use of the

car, their parents can't keep an eye on them. There is a great danger if the driver has been drinking alcohol or

taking drugs, or showing off by speeding or breaking down traffic laws. Mothers of victims (受害者) of such

accidents have formed an organization called MADD (Mothers Against Drunk Driving). These women want to

prevent further tragedies (悲剧). They have worked to encourage the government to limit the youngest drinking

age, Students have formed a similar organization, SADD (Students Against Drunk Driving) and are spreading

the same message among their friends.

     For many Americans the automobile is a necessity. But for some, it is also a mark of social position and for

young people, a sign of becoming an adult. Altogether, cars mean very much to Americans.

1. Which of the following is NOT mentioned in the text?

A. Cars have encouraged the growth of the cities.

B. Cars can bring families together when they go for picnics.

C. Cars have enabled people to live far from their place of work.

D. Cars help city families to transport their children to faraway schools.

2. What has been done to deal with the problem of drunk driving?

A. Patents have paid more attention to their children.

B. Some organizations have been set up against drunk driving.

C. Mothers have tried to persuade their children not to drink alcohol.

D. University students have asked the government to solve the problem.

3. We can infer from the text that _____ in America.

A. it will be more difficult for people to get new cars

B. parents will not allow their children to have their own cars

C. the government will encourage people to use public transportation

D. cars will still be popular though they have caused many problems

单项选择题