单选题 There is no question that the old style of air pollution could kill people. In one week following the infamous "peasouper" fog in December 1952, 4,700 people died in London. Most of these people were elderly and already had heart or lung diseases. A series of these killer fogs eventually led to the British Parliament passing the Clean Air Act which restricted the burning of coal.
Fortunately the effect of smog on the lungs is not so dramatic. Scientists have now conducted a number of laboratory experiments in which volunteers are exposed to ozone inside a steel chamber for a few hours. Even at quite low concentrations there is a reversible fall in lung function, an increase in the irritability of the lungs and evidence of airway inflammation (发炎). Although irritable and inflamed lungs are particularly seen in people with asthma (哮喘) and other lung diseases, these effects of ozone also occur in healthy subjects. Similar changes are also seen after exposure to nitrogen dioxide, although there is some disagreement about the concentration at which they occur.
Other studies have found that people living in areas with high levels of pollution have more symptoms and worse hung function than those living in areas with clean air. Groups of children attending school camps show falls in lung function even at quite low concentrations of ozone. There is also a relationship between ozone levels and hospital admissions for asthma, both in North America and Australia. It is suspected that long-term exposure to smog may result in chronic bronchitis (支气管炎) and emphysema (肺气肿), but this has yet to be proven.
Recently an association has been found between the levels of particles in the air and death rates in North American cities. The reason for this association is not understood and as yet there is no evidence this occurs in Australia. However, we do know that hazy days are associated with more asthma attacks in children.

单选题 Which of the following is NOT the result of laboratory experiments?

单选题 Irritable and inflamed lungs are also seen in people with______.

单选题 Which of the following is NOT mentioned as a possible cause of lung diseases?

【正确答案】 D

【答案解析】[解析] 该题要选择不是lung disease的原因的选项。A、B、C三项都可能是导致肺病的原因。根据文中的“Groups of children attending school camps show fails in lung function even at quite low concentrations of ozone．”可知，这里有助于分析文章的信息来自even at quite tow concentrations of ozone，而非Groups of children attending school camps，即Groups of children attending school camps并无实际作用。因此D项为正确答案。

单选题 The relationship between exposure to______has not yet been determined.

单选题 The association between______has not yet been found in Australia.

【正确答案】 C

【答案解析】[解析] 根据文中的“Recently an association has been found between the levels of particles in the air and deat．h rates in North American cities．The reason for this association is not understood and as yet there is no evidence this occurs in Australia．(最近发现北美空气中微粒的浓度与死亡率之间存在联系，但是原因尚不知晓，而且在澳大利亚并未发现此类现象。)”可知，C项是正确答案。