bicycle car motocycle which one DO you close

I choose bicycle.AS an efficient tool of transportation , bicyle is still popular in China. It is very conbvient for people to go to work or go to school ,especially in the rush hour .When the car drivers are pressing their bugles anxiously,you can go through the waiting lines of cars without any difficulty .But with the development of transportation , more and more people can afford to buy cars . Indeed ,cars can help people go to where they want easily ,but I think cars also make the air dirty . With the 2008 Olympic Games coming ,It is a very important task for us to build a clean city for the whole world ,whereas bicycles can help stay healthy and save energy . So I think I prefer to choose bicycle as my transportation tool instead of cars .