Is sleep important for children? A new study says yes.

In America, most people don't get enough sleep. Children aged 5 to 12 are advised to sleep 10 to 11 hours every night, but most of them can't sleep that long. A study found that about 41 million American workers got less than six hours of sleep every night. Scientists worry that parents are passing their poor sleeping habits down to their children.

In the study, Reut Gruber and some other scientists either added or reduced(减少) one hour of sleep for healthy children aged 7 to 11. They watched the children for five nights. They wanted to know if the amount of sleep can affect(影响) a child's behavior.

Before the study began, students were asked to sleep the same amount of hours as usual. Their teachers were asked to record their behavior. After changing the children's sleep for five nights, the teachers had to record again. According to the two records, scientists found that those who slept one hour less behaved worse than those who slept one hour more. Students with less sleep were more likely(可能的) to feel sad and had more problems paying attention.

The scientists chose to study children in their homes instead of in a laboratory, because they wanted to find out how everyday changes might affect children's behavior at school. "In the study, nobody became a talent, and nobody became crazy. But small changes in children can really make a big difference," says Gruber.

 根据短文内容，完成下列小题。
【小题1】According to scientists, what may cause children to sleep less?
________________________________________________________________________________
【小题2】Why did scientists do the new study?
________________________________________________________________________________
【小题3】Who helped do some records in the new study?
________________________________________________________________________________
【小题4】Who did the scientists find behaved better in the new study?
________________________________________________________________________________
【小题5】Was the study done in a laboratory?
________________________________________________________________________________