Car Engine

A car is the combination of all kinds of technologies, and the heart of it, the engine, is certainly the most complex part. It works in four circulative steps. First, the engine inhales some air into the cylinder. Then, the piston squeezes the air and the gas together. This step makes burning easier and faster. Next, the engine light a fire. The mixture of gas and air suddenly explode. The explosion push the piston to spin. The spinning of the piston provides the energy for car to run. Last, the engine releases the air out to prepare for the new circulation. In my oponion, the engine is always the most amazing and complicated mechine in the world.