问题 配伍题 B型题

对管壳材料的要求是() |对阳极材料的要求是()

A.原子序数高,X线发生效率高

B.熔点低,金属蒸发率低,导电率高,热传导率高

C.熔点高,蒸发率高,容易加工

D.良好的导电性能

E.较高机械强度以承受高真空压力

答案

参考答案:E|A

阅读理解

The world has many beautiful sounds. We can hear the songs of birds and the laugh of people. We can listen to cool music and news reports. And it’s all because of our ears! They bring us a world of sounds.

But some people can’t hear any sound at all. Some are born deaf. Others can hear well in their childhood, nut too many loud sounds hurt their ears later on.

Many people in China can’t hear ordinary sounds clearly. Lots of them are children. Most of them are born with good hearing. But six children of every 1,000 have hearing problems when they are born. And if a children has hearing problems, he or she usually will also have some learning problems at school.

A lot of things can cause fearing problems, like, too much earwax is not good for our hearing. And noise louder than 85 decibels (分贝) can hurt our ears and make us lose our hearing for a short time or even for ever.

Hearing is important for all of us. So we should do our best to give our ears special care. Don’t forget to do the following:

◎ Try to stay away from places with too much noise. If you have to go, wear earplugs.

◎ When swimming, remember to put earplugs into your ears to stop water from getting in.

◎ Never put anything sharp into your ears. If you think you have too much earwax, ask your parents to help you clean it out.

Keep these things in mind. Then you won’t be saying “WHAT? WHAT?” when you are older.

小题1:What does the underlined word “earwax” mean in the passage?

A.耳膜

B.耳鸣

C.耳垢

D.耳疾小题2:Which of the following is NOT talked by the writer?

A.Illness and hearing problems.

B.people with hearing problems.

C.Ways to protect our ears.

D.Danger of loud noise.小题3:____________ is/are bad for our ears.

A.A little earwax

B.Earplugs

C.All noise

D.Noise louder than 85 decibels小题4:The underlined sentence means ___________.

A.When you get older, you know it’s not polite to ask “What?”.

B.When you get older, you still have good hearing.

C.When you get older, you won’t ask questions.

D.When you get older, you will have fewer questions.

多项选择题