bicycle is a convinient means of transporation. it has been very popular in china. during the rush hours, particularly in big cities, you can often see a sea of bicycle riders in the streets. people can ride bicycles to their working places, to schools, to shopping centers and so on. in a word, bicycles play an important role in daily life.
compared with cars, bicycles have many advantages. firstly, they are not so expensive as cars and almost every family can afford to buy and repair them. secondly, riding bicycle is a healthy form of exercise. they do good to our health. thirdly, bicycles can save energy and does not cause any pollution, while cars will cause serious air pollution, which makes the air in our living place very dirty and makes a lot of people suffer from lung cancer. as we all know, china is a country with a large population. ifeach family has a car, a large amount of energy would be wasted and air pollution would become