求高手看看这篇英语文章有没有语法错误,

求高手看看这篇英语文章有没有语法错误,
There are many means of transportation in the world,For example ：trains,cars,planes and boats.These ways are convenient and not very expensive.But I like riding a bike.
Bicycle is a common means of transport in the world.Riding bike can help you to keep health and building muscle.Over-weight people can lose their weight by riding bikes.And it is important that riding bicycle is green and do not pollute the air .When we travel by bike,we can breathe fresh air,enjoy the beauty of the surroundings,forget all the problems.Students should go to school by bikes; it can have no traffic jam and would not be late for class
Please slow cycling,avoid traffic accidents,and ensure the safety of life
That's why I like riding bike.I ride to school everyday,it makes me healthy.
Thank you very much