Traffic lights are very important to us. I think everyone knows this. But how were they born? Do you know?

    Garrett A. Morgan was the father of traffic lights. He was American. Morgan was born in 1875. His family was very poor. He left (离开) school at the age of 14. He was very clever. He always looked for better ways to do things. And he liked to make new things. At that time, every American wanted to have a car. Streets were full of cars. The traffic was not good. "Why not put three lights at each street crossing? They should be red, yellow and green," Morgan said, "Let them tell cars to go or stop." So he made a timer (定时器) to change the lights. Now we have traffic lights on the streets.