Passage Two
[29]Moods, say the experts, are feelings that are likely to be fixed, having effects on one's outlook for hours, days, weeks or even years. That's great if your mood is a pleasant one, but it will be a problem if you are sad, anxious, angry or simply lonely.
Perhaps the best way to deal with such moods is to talk them out; sometimes, though, there is no one to listen. Modern pharmacy offers a lot of anti-anxiety drugs. [30]What many people don't realize, however, is that scientists have discovered the effectiveness of several non-drug methods to make you free from an unwanted mood. These can be just as useful as drugs, and have the added benefit of being non-poisonous. So next time you feel out of sorts, don't head for the drug store-try the following method.
[30]Of all the mood-changing self-help techniques, aerobic exercise seems to be the best cure for a bad mood. "If you could keep the exercise, you'd be in high spirits," says Kathryn Lance, author of Running for Health and Beauty. Researchers have explained biochemical and various other changes that make exercise seem preferable to drugs as a mood-raiser. Physical work such as housework, however, does little. [31]The key is aerobic exercise-running, cycling, walking, swimming, or other repetitive activities that increase the heart rate and circulation, and improve the consumption of oxygen. You may do them for at least 20 minutes a time, three to five times a week.

Questions 29 to 31 are based on the passage you just heard.
29. What is the effect of moods on people?
正確答案：A
解析：細節題。“專家們認為情緒有可能是穩定的，會影響人生觀長達幾小時、幾天、幾周甚至幾年”，故A為答案。
30. What is the best way that most people don't realize to keep a good mood?
正確答案：C
解析：細節題。短文提到，很多人沒有意識到，科學家們已經發現有幾種非藥物的方法可以有效地讓人們遠離焦慮；然后提出其中最好的方法就是aerobic exercise，故C為答案。本題也可以通過排除法解題；A、D為多數人已知的方法；B未提及。
31. According to the speaker, why is aerobic exercise able to cheer people up?
正確答案：D
解析：細節題。短文末尾提到有氧運動提高心率、加快血液循環和改善耗氧量，故答案為D。