A. How to beat a bad mood. B. How to do physical exercises. C. How to talk bad moods out. D. How to be involved in aerobic exercise. 参考答案:A 答案解析:根据第二段可确定短文主题是如何排除优郁的情绪。
第17题: [单项选择]A bottle weighs more after air is put in. proves that air has weight. A. We B. Which C. It D. What 参考答案:C 答案解析:[考点] it的用法 [解析] it在这里代表前面所提到的事实。故选C。注意区分A bottle weighs more after air is put in It proves that