What happens if you don't get enough sleep? Randy Gardner,a high school student in the United States,wanted to find out. He designed an experiment on the effects of sleeplessness for a school science project. With doctors watching him carefully, Gardner stayed awake for 264 hours and 12 minutes. That's eleven days and nights without sleep! What effect did sleeplessness have on Gardner? After 24 hours without sleep, Gardner started having trouble reading and watching television. The words and pictures were too blurry(模糊). By the third day,he was having trouble doing things with his hands. By the fourth day,Gardner was hallucinating(产生幻觉). For example,when he saw a street sign,he thought it was a person. He also imagined he was a famous football player. Over the next few days,Gardner's speech became so slurred(不 清楚)that people couldn't understand him. He also had trouble remembering things. By the eleventh day,Gardner couldn't pass a counting test. In the middle of the test he simply stopped counting. He couldn't remember what he was doing. When Gardner finally went to bed,he slept for 14 hours and 45 minutes. The second night he slept for twelve hours, the third night he slept for ten and one-half hours,and by the fourth night, he had returned to his normal sleep schedule. Even though Gardner recovered quickly,scientists believe that going without sleep can be dangerous. They say that people should not repeat Randy's experiment. Tests on white rats have shown how serious sleeplessness can be. After a few weeks without sleep,the rats started losing their fur(皮毛). And even though the rats ate more food than usual, they lost weight. Eventually the rats died. During your lifetime, you will probably spend 25 years or more sleeping. But why? What is the purpose of sleep? Surprisingly, scientists don't know for sure. Some scientists think we sleep in order to replenish(补充)brain cells. Other scientists think that sleep helps the body to grow and to relieve stress. Whatever the reason, we know that it is important to get enough sleep.
单选题
Randy Gardner studied the effects of over-sleeping.