参考答案

正确答案：Air PollutionThere is obviously a very serious problem of pollution in our cities nowadays. In this short article we shall discuss two problems: the cause of air pollution and possible ways of reducing or controlling it.The first question then is: What cause air pollution? in a typical city there are five main sources of air pollution: waste disposal which is the least important heating power plants industry and cars which alone cause 60% of air pollution in most large cities.The next problem is therefore how to control or reduce air pollution. It seems that we should deal with cars first. There are four main ways of reducing the pollution caused by cars. First we can try to persuade people to use car less. For example we can make cars more expensive. Second we can try to use other forms of transport such as buses. Third we can use a different and cleaner fuel for cars such as electricity and gas. Finally we can try to invent new kinds of engines.
Air PollutionThere is obviously a very serious problem of pollution in our cities nowadays. In this short article, we shall discuss two problems: the cause of air pollution, and possible ways of reducing or controlling it.The first question then is: What cause air pollution? in a typical city there are five main sources of air pollution: waste disposal, which is the least important, heating, power plants, industry, and cars, which alone cause 60% of air pollution in most large cities.The next problem is, therefore, how to control or reduce air pollution. It seems that we should deal with cars first. There are four main ways of reducing the pollution caused by cars. First, we can try to persuade people to use car less. For example, we can make cars more expensive. Second, we can try to use other forms of transport, such as buses. Third, we can use a different and cleaner fuel for cars, such as electricity and gas. Finally, we can try to invent new kinds of engines.