高分英语书面表达的六大特性(2)

　　But a lot of problems are coming about. Traffic in cities is getting heavier and heavier. The car is causing more pollution. To solve these problems, something must be done.

　　此篇书面表达的中心“轿车进入家庭后所产生的影响”，由两个主题句 It has advantages 和 A lot of problems are coming about 体现出来。为了进一步展开主题句 It has advantages，文章从convenience, saving time and developing car industry and economy 三方面加以论证;为了展开主题句 A lot of problems are coming about，文章从 traffic 和 pollution 两方面加以说明。这样利用主题句使文章层层相扣，形不散，神也不散，文章读起来朗朗上口，生动有趣。