The Acronym, our student newspaper, reports that many students go to sleep at 1:30 a. m. _ Scientists say teens should sleep nine hours each night. But that's hard to do. Some even _ . In the morning they don't look good. One of my classmates did a survey on this problem. She found that most kids pull all-nighters to finish homework, but some do it for other reasons, such as playing computer games. I usually go to bed around midnight. If I stay up past l:30 a. m., I won't get any work done. I'll fall asleep at my computer. My classes begin at 7:30 a. m. I am partly awake in my first class. By midday, I am finally wide-awake. But by 3:00 p. m. I am slowing down again. Yet I get more sleep than the Acronym's many students. Most American high schools seem to have a similar problem with sleepy students. High school classes start at 7:30 a. m., so students have to wake up one and a half hours before that to get ready and catch the bus. It's believed that lack of sleep can damage   both grades and health. What's the main problem the passage mentions?
Many kids have too much homework to do. Many teenagers don't have enough sleep. Many children are crazy about playing computer games. Many kids wake up too early.