用英语介绍自行车，汽车、飞机这三种交通工具。（简单一点是初一英语，不下50个单词）

自行车:bike:This is a kind of vehicles.It has two wheels.
汽车:car:This is a kind of vehicles.It has four wheels.
飞机:plane:This is a kind of vehicles.It can fly.

Bike is a kind of vehicles.It has two wheels.

Car is a kind of vehicles.It has four wheels.

Plane is a kind of vehicles.It can fly.

自行车 bike/bicycle--a kind of vehicles(交通工具）,it has two wheels,and it is very convinte（方便）.
汽车 car--a kind of vehicles,clean and safe.
飞机 plane--a kind of vehicles,it is quicker,but more expensive than the other two.

car,bike,plane