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 ________.

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 ________.

Do you know what school life is like in Singapore? In Singapore, a class only lasts half an hour, but there are no breaks between classes. The students only have a 30-minute tea break after 3 or 4 classes.
They do not do eye exercises. Yao Suyu said our eye exercises were unfamiliar(不熟悉)to her. “I’d like to introduce them to our school,” she said. “They’re very useful!”
In Singapore school ends at 1:50 p.m. But students joined other classes after school such as dance clubs and choir(合唱团). Yao says she joins dance club twice a week and it lasts from 1:30 to 5:30 p.m.
Singapore’s population(人口)includes Chinese, Indians(印度人), Malays(马来人 )and Westerners. But there is no special school for any one of the groups. The students in Yao’s school are mainly Chinese, Indians and Malays. “The Indian students take Indian language classes when we study Chinese,” said Yao. “But if an Indian student is interested in Chinese, he or she can study it, too.”
In Singaporean schools, teachers teach in English. It’s the official(官方的)language in Singapore. Singaporean students have to take different courses after school. Like most Singaporean students, Yao took other courses in Chinese, math and English.
【小题1】How long does a class last in Singapore?
                                                                          
【小题2】Do the students do eye exercises in Singapore?
                                                                          
【小题3】When does school end in Singapore?
                                                                          
【小题4】What does Singapore’s population include?
                                                                          
【小题5】In which language do teachers teach in Singaporean schools?