Section C
WHATS IN THE AIR?
Sulphur dioxide contributes to acid rain, which contaminates rivers, streams and lake, causes serious erosion of buildings and endangers wildlife. It also makes breathing problems worse by tightening the tubes which carry air to the lungs.
Nitrous oxides (nitrogen dioxide and nitric oxide gases) cause acid rain and smog! Carbon monoxide reduces the amount of oxygen that can be carried by blood. Peaks occur during rush hours, and high levels are found inside cars.
Hydrocarbons are released when fuel is not completely burned. They can be gases or solids.
Volatile organic compounds (VOCs) are gases which form smog. Benzene escapes from the exhaust pipes of cars and from petrol tanks when cars are filling up.
Ozone is a gas produced naturally in the upper atmosphere. A thin layer of ozone helps to shield the Earth from the sun's damaging rays. At ground level, ozone is the main enemy for people with breathing problems. It is created by the effect of sunlight on smog, a reaction which occurs most easily when weather conditions are calm and warm.
WHERE POLLUTION COMES FROM
Motor vehicles are the fastest-growing source of air pollution today, pumping out a toxic mixture of health-threatening pollutants. Traffic fumes are largely responsible for the increasing number of smogs which pollute our towns, cities and rural areas.
Industry: A lot of pollutants are released into the atmosphere by industrial processes. For example, when coal is burnt in power stations to generate electricity, sulphur dioxide and nitrous oxides are produced. These are the two major gases which cause acid rain.
Waste disposal: When rubbish is burned, the smoke and gases produced often contain pollutants such as dioxins, which are a threat to human health and the environment.
HOW IT AFFECTS YOUR BODY
High concentrations of ozone and the chemicals released by motor vehicles can lead to serious health problems including irritation of the lungs and a reduced resistance to infection. They also aggravate bronchitis and may even cause cancer. Many pollutants can trigger an asthma attack. During levels of peak pollution, doctors advise sufferers to stay indoors and avoid exercise.
GRIM FACTS
? Cars produce 15 percent of worldwide greenhouse gases.
? Car ownership is rising in every country. There are now more cars than adults in the USA.
? It is estimated that the number of cars on the word's roads will rise to 1.5 billion in the next 20 years.
? The number of children admitted to hospital with asthma in the UK has more than doubled since 1980.
问答题
When is the carbon monoxide level at its highest?
【正确答案】During the rush hours.
【答案解析】根据题干中“carbon monoxide”可定位至少第二段第二句，该句指出“一氧化碳会减少血液中的氧气含量”，接着下一句指出“Peaks occur during rush hours, and high levels are found inside cars”，可知一氧化碳含量在上下班高峰期达到顶峰。
问答题
What is ozone created by?
【正确答案】It is created by the effect of sunlight on smog.
【答案解析】第五段主要与臭氧相关，该段最后一句提到“It is created by the effect of sunlight on smog...”，可知臭氧是阳光照射在烟雾上所形成的。
问答题
Which kind of pollutants have caused the increasing number of smogs?
【正确答案】Traffic fumes．
【答案解析】第六段第二句提到“Traffic fumes are largely responsible for the increasing number of smogs...”，即车辆尾气排放是烟雾增多的主要原因。
问答题
What are the main illnesses that air pollution causes?
【正确答案】They include irritation of the lungs and a reduced resistance to infection.
【答案解析】在文中“HOW IT AFFECTS YOUR BODY”部分，开头就指出臭氧和车辆所排放化学物质的集中会导致严重的健康问题，其中包括irritation of the lungs and a reduced resistance to infection“对肺部产生刺激，并且人体抗感染能力下降”。
问答题
How many cars will there be in the world in 20 years' time?
【正确答案】The number of cars will rise to 1.5 billion.