案例一：
Traffic jam is a growing problem in our cities and it is becoming more and more serious the city' s developing.As a result of traffic growing,the city’' s pollution is growing,too.And in the for in some point,we can say it is a big soruce of pollution in cities.
The steam Cars play an important role in modern society.But they are also responsible for a good part of air pollution in big cities.The carbon dioxide is the outcome of transportation and it seriously cause the greenhouse effect.
汽车itAs we know,the sulfur dioxide and nitric oxide are also making by cars.And this two kinds of gas play more important role in city pollution.For people, especially children and elderly people, with breathing problems, polluted air can be very harmful, sometimes even fatal.
In a word ,when you enjoy all the conveniences that the city has to offer, you are paying a price also because the city is more polluted and crowded.And we have to say traffic is a bigs
ource of pollution in cities.
案例二：
Too many cars have caused a lot of serious problems in our world.Besides congestion,accidents and fast fuel consumption, cars are responsible for a good part of air pollution in big cities.
One possible solution is to design and develop clean cars and clean fuels.In Shanghai,some of the public buses begin to run on natural gas, which does not give off as much carbon dioxide as petrol.Another solution is to develop modern public transportation systems and restrict the use of private cars. If the price of petrol rises constantly and the public vehicles are efficient and convenient enough, most people will not buy private cars.Thus, the total number of cars in big cities will reduce greatly.
On the whole, the elimination of air pollution needs the collective efforts from the government, the public and the environmentalists.
发布评论