In China, more and more school students are tired because their sleep time is1 shorter and shorter. Most students can only sleep less than eight hours every night, because they have too much homework 2. Some homework is given by their teachers, and some by their parents. Also, some students don't know 3 to save time. They are not 4 while doing their homework, so it takes them more and more time to finish 5.

    Some students 6 too much time watching TV or playing computer games. They stay up very late. Some students 7 get up early every weekday to get to school on time by bus or by bicycle. It may be a long way from home to 8.

    The homework should be cut down so that the students can feel 9. For the children, they should make good use of their time. More than eight hours of sleep every night is 10 for their health. If they have enough sleep time, they will find it much better for both their study and health.

    Up to two thirds of children don't get as much sleep as they should do, and this can make them nervous and slow at school, researchers say.

    So how long should young people sleep each night? The answer is between 8 and 10 hours. If you don't get enough sleep at night, you'll have less energy the next day.

    But the researchers say many children have missed out on 4,500 hours of sleep by the time they are seven years old. They say that children miss sleep because they have TVs and computers in their rooms, and busy parents don't read to their younger children at night any more. The traditional “bedtime story” helps children to relax and fall asleep peacefully. Children with TVs and computers in their bedrooms were more likely to sleep badly, and to get less than eight hours' sleep. Even losing one hour's sleep a night can mean that children do less well at school.

    German scientists think that your brain keeps working while you're asleep. To show that they were right, they gave two groups of people a problem to work out. One group went to sleep, and the other group stayed awake. The result? The people who slept worked out the answer more quickly, suggesting their brains had been trying to find the answer while the people were asleep. So, make sure you get enough sleep tonight, and you'll be at your best tomorrow!

—She always     .