Getting the proper amount of sleep is also important. If you don't get enough sleep, you feel tired and easily get angry. You have no energy. Over a long period of time a little amount of sleep may even result in a change of personality (人的个性)．Be sure to allow yourself from seven to nine hours of sleep each night. If you do, your body will feel strong and refreshed, and your mind will be sharp.

Finally, get plenty of exercise. Exercise firms the body, strengthens the muscles, and prevents you from gaining weight. It also improves your heart and lungs. If you follow a regular exercise program, you will probably increase your life­span (寿命)．Any kind of exercise is good. Most sports are excellent for keeping the body in good shapes: basketball, swimming, bicycling, running and so on are good examples. Sports are not only good for your body, but they are enjoyable and interesting, too.

If everybody, were to eat the right foods, get plenty of sleep and exercise regularly, the world would be a happier and healthier place. We would all live to be much older and wiser.

文章大意：本文讨论了如何保持健康：合理的饮食；充足的睡眠；适当的锻炼。这是三大法宝。

1．According to the passage, ________.

A．we should always keep fit

B．if we were healthy, we could spend our days in doing things with less sleep

C．one can eat a lot to stay in good shape

D．one needn't take any exercise if he is healthy

答案：A　细节理解题。根据文章第一句Good health is the most valuable thing a person can have, but one cannot take good health for granted.说明健康是一个人最重要的东西，故A正确。