Write a composition entitled Cars and Air Pollution. You shouldwrite at least 120 words according to the outline given below inChiness.
1.汽车越来越多，造成了城市的空气污染;
2.如何解决这一问题;
3.做出总结。
【步骤构思】
步骤1：
审题：这是一篇以汽车和空气污染为主题的解释说明文。
步骤2：
引入话题：越来越多的汽车造成城市空气污染;
展开话题：从两方面说明解决这一问题的办法;
话题结论：大家共同努力，消除汽车造成的空气污染。
【作文背诵范文】
Cars and Air Pollution
Too many cars have created a lot of serious problems in our world. Besides congestion, accidentsand fast fuel consumption, cars are responsible for a good part of air pollution in big cities. All thetime，they are releasing huge amounts of waste gases into the atmosphere. These gases are veryharmful, causing diseases and even death.
太多的汽车已经给我们的世界制造了许多严重的问题。除了堵车、事故和快速的燃料消耗之外，汽车对大城市的空气污染有很大一部分责任。一直以来，汽车向大气中释放大量的废气。这些气体非常有害，会导致疾病甚至死亡。
So serious is the problem that we must find some solutions to it. One possible solution is to designand develop clean cars and clean fuels. In Shanghai, some of the public buses begin to run onnatural gas， which does not give off as much carbon dioxide as petrol. But it may take decadesfor the new models of clean cars to complete1y replace the traditional ones. Another solution is todevelop modern public transportation systems and restrict the use of private cars. If the price ofpetrol rises constantly and the public vehicles are efficient and environment enough, most peoplewill not buy private cars. And the total number of cars in big cities will reduce greatly.
问题如此严峻，我们必须找到一些解决方法。一种可能的解决方法就是设计和研发清洁汽车和清洁燃料。在上海，一些公交车开始使用天然气，天然气不像汽油那样释放那么多二氧化碳。但是，要使新型的清洁汽车完全替代传统汽车，可能需要几十年的时间。另一个解决方法是发展现代公共交通系统，限制私家车的使用。如果石油价格持续上涨，公交车变得有效率且足够环保，那么大部分人就不会买私家车了。而大城市汽车的总数会大大减少。
On the whole, with the collective efforts of all parts concemed, the elimination of air pollutioncaused by cars will be solved in the near future. (202 words)
总之， 有了所有相关方面的共同努力，消除由汽车造成的空气污染问题会在不远的将来得到解决。
【高分句型解析】
In Shangbai, some of the public buses begin to run on natural gas, which does not give off asmuch carbon dioxide as petrol. 在上海，一些公交车开始使用天然气，天然气不像汽油那样释放那么多二氧化碳。
点评：这是一个由which引导的非限制性定语从句，which指代的内容是前面的natural gas。
【作文加分词】
congestion [kən'dʒestʃən] n.拥塞，拥挤
consumption [kən'sʌmpʃn] n.消费，消耗
give off 发出，释放出
restrict [ri'strikt] v.限制，限定
constantly ['ka: nstəntli] adv.不断地
the collective efforts 共同努力，集体努力
elimination [i,limi'neiʃn] n.消除， 根除
