Cigarette smoking is believed by most research workers in this field to be an important factor in the development of cancer of the lungs and the throat and is believed to be related to cancer of the bladder(膀胱) and the oral cavity(口腔). Male cigarette smokers have a higher death rate from heart disease than non-smoking males.
　　
　　Female smokers are thought to be less affected be cause they do not breathe in the smoke so deeply. The majority of physicians and researchers consider these relationships proved to their satisfaction and say. "Give up smoking. If you don't smoke, don't start". Some competent physicians and research workers - though their small number is dwindling(減小) even further-are less sure of the effect of cigarette smoking on health. They consider the increase in respiratory (呼吸的) diseases and various forms of cancer may possibly be explained by other factors in the complex human environment - atmospheric pollution, increased nervous stress, chemical substances in processed food, or Chemical pesticides that are now being used by farmers in vast Quantities to destroy insects and small animals. Smokers who develop cancer or lung diseases, they say, may also, by coincidence, live in industrial areas, or eat more canned food. Gradually, however, research is isolating all other possible factors and proving them to be statistically irrelevant. While all tobacco smoking affects life expectancy and health, cigarette smoking appears to have a much greater effect than cigar or pipe smoking. However, nicotine(尼古丁)consumption is not diminished by the latter forms, and current research Indicates relationship between all forms of smoking and cancer of the mouth and throat. Filters and low tar(焦油) tobacco are claimed to made smoking to some extent safer, but they can only marginally reduce ,not eliminate, the hazards.
　　
1. Male smoking are more affected by smoking than female ones because _____.
[A] Male smokers smoke more than female ones
[B] Male smokers are more likely to be affected by smoking
[C] Male smokers breath in the smoke deeper than female ones
[D] Male smokers are more likely to be affected by other factors in hormone environment

2. According to the passage,cigarette can do harm to all the following EXCEPT _____.
[A] lung
[B] mouth
[C] heart
[D] eye

3. The author's attitude towards smoking is _____.
[A] critical
[B] approving
[C] questioning
[D] subjective

4. Which of the following statements is NOT TRUE?
[A] More and more research work believe the effect of cigarette smoking on health.
[B] Filters and low tar tobacco can not get rid of the hazard.
[C] Cigarette smiking has a greater effect on health than.
[D] All forms of tobacco smoking affects life expectancy and health.

5. The authors purpose of writing the passage is to _____.
[A] offer advice on how to give up smoking
[B] explain the influence of cigarette smoking on health
[C] list the factors that can cause cancer
[D] compare the opinions on the effect of smoking