题目内容：

Sweet Dreams While You Sleep

Did you sleep the day away on Friday March 21? Well, you should have done that because it was World Sleeping Day.

This is the day of the year when people around the world care about their sleep and ask themselves questions about sleep.

Why do we need sleep?

Nobody as yet can give a perfect answer to this question. However, lab tests on rats have shown that lack (缺少) of sleep over about four weeks leads to a strong drop in body temperature, great weight loss and finally, death.

How much sleep?

Different people need different amounts of sleep. Eight hours a night is considered the average amount of sleep. For teenagers, the least number of sleeping hours advised by doctors are 10 hours for primary school students, nine for junior highs and eight for senior highs.

Some people seem to get along just well with very little sleep at night. Leading American scientist Thomas Edison, for example thought of sleep to be a waste of time. He did, however take naps (打盹) during the day. On the other hand, Albert Einstein, another great scientist, said he needed at least ten hours sleep a night.

How can we sleep well?

Here are some of the most popular tips for a good night's sleep:

*Listen to your body clock, not your alarm clock (闹钟).

*Use your bed only to sleep.

*Get up and go to bed at the same time (also on weekends).

*Exercise in the morning and in the early afternoon. Don't exercise in the evening.

*Stop looking at that clock while you can't sleep! And don't worry.

*Avoid alcohol (酒精), caffeine (咖啡因) and smoking before going to bed.

*Keep the bedroom dark, quiet, and cool.

1.Which of the following is true according to the passage?

A. Thomas Edison slept very long hours every day.

B. Albert Einstein needed very little sleep.

C. Doctors suggested that primary school students have ten hours of sleep.

D. Doctors suggested that junior highs have eight hours of sleep.

2.Which of the following is not a good sleeping habit?

A. Have a cup of alcohol before going to bed.

B. Keep the bedroom dark, quiet and cool.

C. Get up and go to bed at the same time.

D. Listen to your body clock.

3.What is implied in this passage?

A. Bedrooms can be used for other purposes.

B. Great scientists need less sleep than ordinary people.

C. World sleeping day is the only time when people become concerned about sleep.

D. Results from lab tests on rats may be applicable to humans.