单项选择题

A. To chat with Jack socially.
B. To get help in the course.
C. To hand in their assignments.
D. To practice giving interviews.
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单项选择题
A. $190,000. B. $330,000. C. $500,000. D. $1,000,000.
A. $190,000. B. $330,000. C. $500,000. D. $1,000,000.
填空题
The judgment that cigarette smoking is hazardous to health is the result of more than 30 years of research carded on by hundreds of scientists in this country and abroad. The conclusion that cigarette smoking is a (26) health hazard is supported by every medical and health (27) in the world which is known to have (28) an opinion on the matter. While cigarette smokers tend to have higher death rates than nonsmokers. 80% of the excess deaths (29) with this habit are caused by three major diseases. They are lung cancer, coronary heart disease, and emphysema. Lung cancer was a (30) disease 50 years ago. Today, it is (31) that 60,000 men and women per year in the United States will die of this disease. Among men it is the most (32) cause of death from cancer. Cigarette smoking is the major cause of lung cancer. Although chronic (33) from certain chemical substances, radiation, (34) , occupational hazards, air pollution, and other environmental factors have been implicated in this disease, they are of small importance compared with cigarette smoking. To those who smoke, however, they Can be important in increasing the risks still further. (35) 90 percent of all primary cancer cases occur in people who smoke cigarettes. Laboratory studies have isolated from tobacco smoke a number of chemical compounds that can cause cancer. In addition, there are elements in smoke that interact with other compounds to promote cancer production.
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