问题 单项选择题

当第二相粒子与基体呈共格关系时,此时所看到的粒子大小()。

A.小于真实粒子大小;

B.是应变场大小;

C.与真实粒子一样大小;

D.远远大于真实粒子

答案

参考答案:B

阅读理解

     People believe that climbing can do good to health. Where can you learn the skill of climbing then?

If you think that you have to go to the mountains to learn how to climb, you're wrong. Many Americans

are learning to climb in city gyms (体育馆). Here, people are learning on special climbing walls. The

climbing wall goes straight up and has small holding places for hands and feet.

     How do people climb the wall? To climb, you need special shoes and a harness(保护带) around

your chest to hold you. There are ropes (绳索)tied to your harness. The ropes hold you in place so

that you don't fall. A beginner's wall is usually about 15 feet high, and you climb straight up. There are

small pieces of metal that stick out for you to stand on and hold on to. Sometimes it's easy to see the

new piece of metal. Sometimes, it's not. The most difficult part is to control your fear. It's normal for

humans to be afraid of falling, so it's difficult not to feel fear. But when you move away from the wall,

the harness and the ropes hold you, and you begin to feel safe. You move slowly until you reach the

top.

     Climbing attracts people because it's good exercise for almost everyone. You use your whole body,

especially your arms and legs. This sport gives your body a complete workout. When you climb, both

your mind and your body can become stronger.

1. What can we infer from the passage?

A. People are fairly interested in climbing nowadays.

B. It is impossible to build up one's body by climbing.

C. People can only learn the skill of climbing outdoors.

D. It is always easy to see holding places in climbing.

2. The most difficult thing to do in wall climbing is _______.

A. to tie ropes to your harness

B. to control your fear

C. to move away from the wall

D. to climb straight up

3. The word "workout" underlined in the last paragraph most probably means _______.

A. settlement

B. exercise

C. excitement

D. tiredness

4. Why does the author write this passage?

A. To tell people where to find gyms.

B. To prove the basic need for climbing.

C. To encourage people to climb mountains.

D. Introduce the sport of wall climbing

问答题 简答题