自行车(Bicycles)
when we are used to the cars running in the streets now, we may forget the life with bicycles. tens of years ago, people used to go to work by bike. bicycles are cheap and convenient.
　　so many bicycles in the street used to be a great view. in fact,riding bicycles is a good exercise to keep healthy. and it helps to prevent the air pollution. we'd better ride bicycles as often as we can.