Most people need eight hours' sleep every night. Scientists have found that people who sleep for less than six             a half hours a night are more often ill than people who sleep for eight hours. People who sleep for less than five hours often die young, and do less well             work. Sleep is really important to people's lives. Good             needs good sleep.
"But not too much of it," says Professor Jim Home of Loughborough University. "Sleep is like             and drink. You would always like to have a little bit more,  but that doesn't mean you need it." He found that people who sleep for more than             hours a night die younger than people who usually sleep for seven or eight!

科目 英语   题型 选词填空   难度 中等

知识点： 选词填空