说起自行车，很多人认为在很多的大城市，它已经过时了。但是，一些人认为自行车并不过时，他们可以通过骑自行车来锻炼身体。就我看来，我认为骑自行车有很多好处。

　　第一，骑自行车可以让我们更健康。很多人忙于工作，没有时间去锻炼自己。但是如果他们骑自行车上班的话，那么他们可以经常锻炼自己。因此也会变得更加健康。

　　第二，自行车很环保。在几乎所有的大城市里，平均气温要比乡村高，因为城市里有大量的尾气排放到空气中。我们知道，很多在大城市里工作的人都喜欢开车上班，而不是乘公共交通工具。因此，空气会被大量的汽车尾气污染。如果更多的人参与到骑单车去上班的大军中来，那么我们的空气质量也会有显著改善。

　　总之，骑自行车不仅能让我们更加健康，而且也有利于环境保护。我们应该鼓励更多的人来骑单车，而不是开车。

　　Speaking of bicycle, some people think it has outdated in many big cities. However, some people think that it is still popular for them because people can exercise themselves by riding bicycle. For me, I think people can get lots of benefits from riding bicycles.

　　First, we can become healthier by riding bicycles. Since people are busy with works, they have almost no time to do exercise. But if they ride bike to work, then they can practice themselves quite often. Consequently, they will be healthier.

　　Secondly, bicycle is good for our environment. In almost all big cities, the average temperature is a bit higher than countryside for there are too many car emissions there. We all know that people in big cities like to drive cars to go to work rather than taking public transportations. Therefore, our environment is polluted by lots of emissions. If more people join in the trend to ride bicycles to work, then our air quality will be improved obviously.

　　In conclusion, riding bicycle not only can make us healthier but also it is good for protecting our environment. So, we should encourage more people to ride bicycles quite often than driving cars.