traffic light

Traffic lights are very important for keeping people safe (安全) on the road. They help control (控制) when vehicles (车辆) and people should stop or go. A traffic light has three colors: red, yellow, and green.

The red light means stop. When the red light is on, vehicles and people must wait. They cannot move. The yellow light means slow down (减速). It tells drivers (司机) the light will change soon. The green light means go. When the light is green, vehicles can drive, and people can walk if it is safe.

The first traffic light was used in 1868 in London, England. It was very different (不同的) from the lights we use today. It was powered (供电) by gas (煤气), not electricity (电). It only had two colors: red and green. In 1920, the first electric (电的) traffic light was invented (发明) in the United States. This made it easier to control traffic.

Traffic lights are not only for cars. They also help pedestrians (行人) cross (穿越) the road safely. In many countries, there are special traffic lights for pedestrians. They show a walking person or a hand to tell people when it is safe to cross the street.

In some places, traffic lights are used in fun ways. In Japan, for example, there are traffic lights with pictures of cute animals or characters. This makes it easier for children to understand the rules.

Traffic lights help keep the roads safe. They prevent (预防) accidents (事故) and help everyone travel safely. Whether you are driving a car or walking, always follow the traffic lights and stay safe.