用英语写一篇题为“The advantages of riding a bike”的文章，谈谈骑自行车出行的优点

There are many benefits riding a bicycle. It's very environmental-friendly since bicyles only require human force to operate. They won't pollute the air with toxic gas. When riding a bike, you are doing physical exercise so it will make you in shape. A bike is also much cheaper than a car, any students could afford a simple bike. And it's very convenient to park.