Early to bed and early to rise makes a man healthy, wealthy and wise. This is an old English saying ( 谚语 ). It means that we should go to bed early at night and get up early in the morning. If we do, we shall be healthy. We shall also be rich and clever. Is this true? Perhaps it is. The body must have enough sleep. Children of your age need ten hours ’ sleep every night. If you go to bed late, you can ’ t have enough sleep. Then you can ’ t think carefully and your homework will be wrong. Y ou will not be wise and you may not become wealthy! Some people go to bed late at night and get up late in the morning. This is not good for them. We should sleep at night when it is dark. The dark helps us sleep well. When the daylight comes, we should get up. This is the time for exercise. If the body is not used, it will become weak. Exercise keeps it strong. Exercise helps the blood ( 血液 ) to move around inside the body. Blood takes nutrition ( 营养 ) to all parts of our bodies. The brains ( 大脑 ) in our heads also need blood. We think with our brains. If we keep our bodies healthy, and take exercise, we can think better! O u r bodies also need air to breathe ( 呼吸 ). Without air we will die. Get up early in the morning and we can have plenty of clean, fresh air. That will keep us healthy and happy.