第3部分：概括大意与完成句子(第23～30题，每题l分，共8分)
下面的短文后有2项测试任务：(1)第23-26题要求从所给的6个选项中为第2～5段每段选择1个最佳标题;(2)第27-30题要求从所给的6个选项中为每个句子确定1个最佳选项。
Ways to Reduce Exposure to Air Pollution
1 A report published recently brings bad news about air pollution. It suggests that it could be as damaging to our health as exposure to the radiation from the l986 Ukraine nuclear power plant disaster. The report was published by the UKS Royal Commission on Environmental Pollution. But what can city people do to reduce exposure to air pollution? Quite a lot, it turns out.
2 Avoid walking in busy streets. Choose side streets and parks instead. Pollution levels can fall a considerable amount just by moving a few meters away from the main pollution source - exhaust fumes(废气). Also dont walk behind smokers. Walk on the windward(顶风的)side of the street where exposure of pollutants(污染物)can be 50 percent less than on the downwind(顺风的)side.
3 Sitting on the drivers side of a bus can increase your exposure by l0 percent, compared with sitting on the side nearest the pavement. Sitting upstairs on a double-decker(双层电车)can reduce exposure. It is difficult to say whether traveling on an underground train is better or worse than taking the bus. Air pollution on underground trains tends to be less toxic(有毒的)than that at street level, because underground pollution is mostly made up of tiny iron particles(粒子)thrown up by wheels hitting the rails, while diesel(柴油机)and petrol fumes have a mixture of pollutants.
4 When you are crossing a road, stand well back from the curb(路缘)while you wait for the light to change. Every meter really does count when you are close to traffic. As the traffic begins to move, fumes can be reduced in just a few seconds. So holding your breath for just a moment can make a difference, even though it might sound silly.
5 There are large sudden pollution increases during rush hours. Pollution levels fall during nighttime. The time of year also makes a big difference. Pollution levels tend to be at their lowest during spring and autumn when winds are freshest. Extreme cold or hot weather has a trapping effect and tends to cause a build-up of pollutants.
23 Paragraph 2
24 Paragraph 3__________
25 Paragraph 4__________
26 Paragraph 5__________
A Where you stand while waiting to cross
B Where you walk
C Where you sit on a bus and how you
D When you go to bed
E When pollution levels rise and
F When you get up
27 Air pollution can be as harmful to ones health .
28 Traveling on an underground train can reduce exposure .
29 Pollution levels are lower .
30 Its wise to stay away from heavy traffic .
A during rush hours
B in spring and autumn
C to toxic air
D between autumn and winter
E as exposure to nuclear radiation
F on the downwind side