Wake up, boys and girls! Put up your hand if ...

Wake up, boys and girls! Put up your hand if you try to repair your tired body by sleeping in(睡懒觉)on weekends. A new study says the habit might not be a good idea for your health.

The ten-day study came out in the magazine Current Biology. Volunteers were divided into three groups. The first group enjoyed nine hours' sleep each night. The second group was allowed to sleep only five hours each night. The third group was given five hours' sleep Monday through Friday.1.But they were put back on the short sleep schedule the next Monday.

Both the second and third groups ate more snacks at night and put on weight. They also saw a decrease (减少) in insulin sensitivity (胰岛素敏感性), a warning sign for diabetes (糖尿病). Researchers have long known a tack (缺乏) of sleep can increase health risks.2.

"Even though people in the third group slept as much as they could on the weekend, it was not enough," said Dr Kenneth Wright, who led the study. "When they went back to the short sleep schedule the next week, their body failed to control blood sugar. 3.

So what should we do if sleeping in over the weekend is not a good choice? 4. Cut out the "sleep stealers" such as watching television shows or spending time on computers or mobile phones. Always remember. Getting enough sleep is as important as having good caring habits or doing exercise regularly.

A.That was partly because their biological clock (生物钟) had been changed.

B.People can repair their tired body by sleeping in on weekends.

C.But it was surprising that the third group had been worse than the second one.

D.Dr Wright gave advice in two words: sleep longer.

E.And then they were allowed to sleep as much as they liked over a weekend.

九年级英语补全短文5选4困难题