Directions: Read the following passage carefully and then translate the underlined sentences into Chinese. Write your answer on the Answer Sheet. 【B1】It is not surprising then, that so many Americans are trying to improve the condition of their body. They are trying to become more physically fit.【B2】 This is especially true of people over the age of 30. There are reports, however, that Americans in their 20’s may be exercising less. Physical fitness does not guarantee good health. Accidents and disease can happen to anyone at any time. But medical experts say that fitness provides a big step toward living a long and healthy life. Scientists say exercise strengthens the most important muscle in our body-our heart. Exercise increases the level at which we burn fat. 【B3】 It lowers the chance of heart disease, high blood pressure, and diabetes（糖尿病） . It prevents some kinds of cancers. And it prevents loss of bone strength.

We have been talking about exercise and physical fitness. Yet research shows that exercise can improve mental- fitness and our emotions. 【B4】 Scientists have known for some time that exercise can increase the amount of brain chemicals called endorphins（内啡肽） . When the brain releases endorphins, a person feels happier. 【B5】 The condition has been compared to the high feelings caused by taking some drugs. This increased sense of happiness is sometimes called “runner’s high”. Recent studies on animals also show that mental fitness seems to improve with physical fitness. The animals’ brain seems to work better when they exercise.