题目内容
Do you know why you sleep? You may think it’s because you’re tired. Or perhaps you’ve been told sleep is good for you. Yet no one knows exactly why or how people sleep.Until the early 1950s, most scientists thought the body and brain rested during sleep. Then a scientist watched people sleep. He noticed that during periods of between 5 and 30 minutes each, sleepers’ eyes made rapid movements, as if they were watching something. He called these periods REM sleep, for Rapid Eye Movement. Periods when sleepers’ eyes did not move he called non-REM sleep.
Whenever the scientist woke people during REM sleep, they were having vivid dreams. Measurements showed that sleepers’ pulses（脉搏）went up quickly during REM sleep. Their breathing, heartbeat, and the blood going to the brain also increased. Far from being a time of rest, REM sleep is a time when the body is hard at work. Scientists still don’t know the reason for this. Some believe REM sleep makes learning easier. Babies spend a lot of time in REM sleep. Because of this, some scientists believe that REM sleep helps the brain grow. Others think REM sleep is a time for the brain to empty the day’s garbage.
One thing all the scientists agree on is that sleep is necessary. Without enough sleep, people make mistakes. Most major car accidents happen during the early morning hours, when people are sleepiest.
【小题1】During REM sleep, a person’s breathing and heartbeat ________.
| A．stop | B．increase | C．decrease | D．stay the same |
| A．easier | B．empty | C．vivid | D．quickly |
| A．1 | B．2 | C．3 | D．4 |
| A．REM sleep helps the brain grow. |
| B．REM sleep has been watched and recorded by scientists. |
| C．REM sleep is a time to empty the day’s garbage. |
| D．REM sleep is an active time when the body is hard at work. |
| A．has a restful effect on people |
| B．can be avoided with lots of sleep |
| C．is something that all people experience |
| D．is something that all scientists agree on |
【小题1】B
【小题1】C
【小题1】D
【小题1】B
【小题1】A解析:
略
尖子生新课堂课时作业系列答案
英才计划同步课时高效训练系列答案Long, long ago there was a very foolish thief. Do you know what he did one day? When he wanted to steal (偷) the bell on his neighbor’s door, he walked up to the door, took hold of (抓住) the bell and pulled hard. The bell made a very loud noise. The thief was afraid and went home.
Then he sat down to think, “I must do something about the noise,” he said. He thought and thought. At last he had an idea. “Ah, I’ll put some cotton in my ears. Then I won’t be able to hear the noise.” The next day he went to the door of his neighbor, and took hold of the bell. This time he pulled even harder. The bell rang loudly, but the thief did not hear anything. With another hard pull he got the bell out. Just then the neighbor came running out. “Steal my bell? I’ll teach you a lesson (教训),”the angry man shouted. And he hit the thief on the nose.
The foolish thief did not know how the neighbor found out he was stealing the bell. “Why did he come out just then?” he wondered (感到疑惑).
【小题1】The thief was trying to get .
| A．his neighbor | B．his neighbor’s doorbell |
| C．some cotton | D．a door with a bell on it |
| A．safe | B．difficult | C．dangerous | D．easy |
| A．he knew his doorbell was being stolen |
| B．he thought someone was eager (渴望的) to visit him |
| C．He realized (意识到) something strange happened |
| D．Both B and C |
| A．give him lessons | B．punish (惩罚) him for stealing |
| C．help him with the bell | D．be his teacher |
| A．The thief understood why he was hit on the nose. |
| B．The thief knew why the neighbor came out. |
| C．The thief thought the neighbor could not hear the bell. |
| D．The thief didn’t want to know why the neighbor ran out just at the time he stole the doorbell. |