51. 某英文报社正在举办题为“Green Transportation” 的征文活动。请就此题目写一篇英文短文应征，内容包括：
①At present, with the increasing awareness of environmental protection, the topic of green transportation has attracted more and more attention. The reason is that the increase of private cars has brought more and more serious air pollution and traffic jams in our city, especially in the rush hour.
②Therefore I think it’s time to promote the green transportation. In my opinion, first and foremost, we’d better not travel by car unless it’s necessary. In addition, people should be encouraged to choose the public transport. They can take a bus or the light rail. They can even go by underground. These ways of travel can save energy and reduce air pollution .They can also improve the traffic condition. Last but not least, we should choose to walk or ride a bicycle if we don’t go far away. Travelling on foot or by bike provide us with a chance to make us stronger and healthier.
③In a word , I believe that we can improve the environment as well as our traffic condition if we all choose the green transportation.