[简答题]我国是第一自行车大国，使用自行车有很多的好处。但随着经济（economy）的发展，越来越多的家庭购买了小汽车。请根据这些情况写一篇英语文章，阐述一下自行车和汽车各自的优缺点，并谈谈自己的看法。注意：词数在80词以上。

参考答案: China has the largest number of bicycles. Bicycles are still popular all over the world because of their outstanding advantages. It’s convenient to go to school or go to work by bike. It can help people keep healthy to ride often. However, with the development of economy, more and more people buy cars. The exhaust gas from cars pollutes the air. More and more cars have brought heavy traffic problems. I prefer riding bicycles because it is cheap and keeps the air clean.