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 lung 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?
A. Low concentrations
B. Fall in lung function
C. Irritability of the lungs
D. Air way inflammation
【正确答案】
A
【答案解析】
单选题
Irritable and inflamed lungs are also seen in people with ______.
A. asthma
B. lung diseases
C. good health
D. weak health
【正确答案】
C
【答案解析】
单选题
Which of the following is NOT mentioned as a possible cause of lung
diseases?
A. The burning of coal
B. Long-term exposure to smog
C. Exposure to nitrogen dioxide
D. Attending school camps
【正确答案】
D
【答案解析】
单选题
The relationship between exposure to ______ has not yet been
determined.
A. ozone and fall in lung function
B. ozone and lung diseases such as asthma
C. nitrogen dioxide and worse lung function
D. smog and chronic bronchitis and emphysema
【正确答案】
D
【答案解析】
单选题
The association between ______ has not yet been found in Australia.
A. ozone levels and hospital admissions for asthma
B. hazy days and more asthma attacks in children
C. the levels of particles in the air and death rates