【正确答案】 C

【答案解析】[听力原文]26-28
There Yale University professors agreed in a panel disussion to night that the automobile was what one of them called" Public Health Enemy No. I in this county '. Besides polluting the air and conges ting the cities, automobiles could cause heart disease "because we don't walk anywhere any more," said Dr. H. P. Richard Weiner man, professor of medicine and public health. Dr. Weinerman's sharp indictment of the automobile came in a discussion of human environment on Yale Reports, a radio program broadcast by Station WTIC in Hartford, Connecticut. The program opened a three-part series on "Staying Alive". "For the first time in human history, the problem of man's survival has to do with his control of man-made hazards," Dr. Weinerman said. "Before this, the problem had been the control of natured hazards."
26. What is the main idea of the passage?

[详细解答] 文章第一句即为主题句，此句中后半句“…the automobile was what one of them called 'Public Health Enemy No. 1 in this country'”点明了文章中心：汽车是公众健康的头号敌人。因此选项C汽车威胁着人的健康，是正确答案。

【正确答案】 D

【答案解析】[听力原文]
Why could automobiles cause heart disease?

[详细解答] 从文章中的第二句话，“…because we don't walk anywhere any more,...”可知以车代步容易引发疾病，影响人的身体健康。

【正确答案】 D

【答案解析】[听力原文]
For the 1st time, what does the problem of man's survival have to do with?

[详细解答] 只要听到此句，“For the 1 st time in human history，the problem of man's survival has to do with his control of man—made hazards．”就知道人类是第一次处理人造公害的控制问题。