Walking in any high school during the first class in the morning, you will find many stude

Walking in any high school during the first class in the morning, you will find many students are struggling to stay awake.
“They’re sitting in the classroom, but their heads are at home on the pillows,” said a teacher from a high school.
Don’t blame them; blame the clocks in their brains. A research suggests that biological clocks make teens stay up at night and sleep in the morning.
During the first several weeks of school, students are more likely to lack sleep. In the holidays, students can sleep eight hours a night, but during the school days, they sleep only about six hours on average. Students lose 10 hours’ sleep a week. This may affect their school performances and leads to poor health.
Scientists in the US did research to reset teenagers’ biological clock to help them fall asleep earlier. They found the brain can produce a chemical that helps sleep. But it es out only in the dark. So they use a special light in the classroom to try to force a reset of the students’ biological clock.
The research failed in the end. So some schools in the US tried to reset their school time from 7:25 a.m. to 8:30 a.m. The results seemed to be good.
【小题1】What can you see while walking in high schools in the early morning ? (no more than 7 words    2 分)
【小题2】Why are students so sleepy in the first class ? ( no more than 6 words  3分)
【小题3】During the school days, how many hours of sleep do the students lose every month?
( no more than 2 words   2分)
【小题4】What suggestion will the scientists give to high schools? ( no more than 4 words 3分)Many students are struggling to stay awake.