根据首字母提示填空，每空一词。   
    Experts say that students usually need eight or ten hours' sleep at night, but most Chinese students don't get e sleep. Some Chinese parents are usually glad to see their children s late. They will think their children work hard. But not all parents are happy about this. Once a mother t us that every morning her ten-year-old boy put up one finger w his eyes still closed, begging （乞求） for one minute to sleep. Like thousands of "early birds" in China, he has to get up b six every morning.
    A report s that without a good night's sleep, students seem to be weaker t they should be. Many students have fallen asleep during class at one time or another. Too much homework is not the only reason w students stay up late. Watching TV or playing computer games late into night is a  a reason.
    Experts have ever said that students should have good study habits. So some clever students n study late, they are able to work well in class.