green transportation is riding a bike

In a modern city, there are many means of transportation, such as subway, taxi, bus and so on. But my favorite means of transportation is by bike。 First, riding a bike is good for keeping healthy. I spend one hour riding a bike to my office on my working day, and I think it is a good form of physical exercise. Secondly, it is money-saving. Recently, the private car drivers always complain the price of gas is higher and higher, but if you ride a bike, it will cost you nothing. Thirdly, it is beneficial for protecting the environment, so it is a “green ”form of transportation.Therefore, although it has some disadvantages, I like riding a bike best.