Bicycle riding is good exercise.It helps people become fit and healthy. We used to use bicycle a lot as a main transportation tool. Whereever you went you would see the streets and roads were full of bicylces. As the rapid economic development of our country in the last two decades more and more cars and motor bicycles have come into our life. Overwhelmingly cars have replaced bicycles due to their fast speed and comfortable riding envioronment. However, cars have caused huge air pullution and traffic jam, which have brought us many negative influences . Due to the reduced physical activity, heavily polluted air our health have deteriorate. Many people died very young. To improve the situation we should renovate the public transportation facilities and use more bicycles to replace the cars in the future, especially in urban area.
