A good night’s sleep can improve your mood and your memory. New data shows that getting enough sleep might also get your cuts to grow back together faster. In fact, sleep was more important than good healthy food in speeding wound growing back together.

This wasn’t what scientists had expected to see.

They had hoped to show that giving people the right type of food for good health and growth would make their skin wounds grow back together faster --- even in people who were prevented from having enough sleep. The scientists thought it should work because good healthy food keeps the body strong, helps repair injuries and guards against infection (感染).

Tracey Smith is a scientist at the U.S. Army Research Institute. She and her team studied three groups of healthy people who came to their lab to take part in tests. They gave each group small skin wounds.

* One group of 16 volunteers got a normal amount of sleep --- seven to nine hours a night. The other two groups of 20 people each got only two hours of sleep a night, for three nights in a row. To stay awake, the volunteers were asked to do things such as walking, playing video games, watching TV, sitting on an exercise ball or playing table tennis. Throughout the experiment, one of the sleep-losing groups got a healthy drink with protein and vitamins. The other group also got a drink: It looked and tasted the same but had no healthy chemicals in it.

Sleep clearly helped. People who slept normally got well in about 4.2 days. The volunteers without enough sleep took about 5 days. And getting better healthy food offered no clear benefit. What to make of the data

Sleep expert Clete Kushida didn’t find the results all that surprising. He is a doctor at Stanford University Medical Center in California. The idea that lost sleep harms the body is true.

Why didn’t healthy food help healing time? Smith can think of a few possibilities. The healthy drinks may have helped a little --- just not enough to show up clearly in the small numbers of men and women tested here. Different people need different amount of time to become better.

For people who can’t avoid losing sleep, scientists still don’t have a good way to help them. Smith says, “If you want to become better faster, your best bet for now is to get more ‘vitamin Z’.

【小题1】What did the scientists think of this experiment at first?

A．They expected that good healthy food could help people’s skin wounds grow back together faster even without enough sleep.

B．They believe that enough sleep was more important than healthy food because it kept the body strong and helped repair injuries.

C．They thought that without enough sleep it was hard for the skin cuts to become better because the right type of food didn’t work.

D．They wondered which type of way was more helpful and useful to skin injuries, enough sleep or the right type of healthy food.

【小题2】Why did the writer write the paragraph with a “*”?

A．To show how right the scientists’ prediction was.	B．To introduce which group worked better.
C．To tell readers how the experiment was.	D．To show what volunteers took part in it.

【小题3】Sleep expert Clete Kushida didn’t find the result all that surprising because  .

A．he thinks healthy drinks just helped a little because not everyone needs them

B．he believes different people need spend different time in becoming better

C．he guesses the drinks may be not healthy enough to work properly

D．he thinks not having enough sleep is bad for people’s body and health

【小题4】What does Smith refer ‘vitamin Z’ to in the sentence “If you want to become better faster, your best bet for now is to get more ‘vitamin Z’?

A．A vitamin called Z.	B．A helpful healthy chemical.
C．A vitamin which is helpful to wound.	D．sleep.

【小题5】What’s the best title for this article?

A．A useful and helpful report on sleep	B．Sleep makes wounds better faster
C．Healthy food helps repair injuries	D．A useful and important experiment