专题08 2021年中考英语阅读精选真题模拟题精讲练

Passage 8 Traffic Signals A Intensive Reading The idea that red means stop and green means go has influenced our lives in more ways than just traffic signals. We have been taught from a young age that the color red means danger and green means it's okay to move forward. But why were those colors chosen for traffic lights in the first place? For something we have to look at every day, why couldn't they have been prettier colors? Well, it's important to know that before traffic lights for cars, there were traffic signals for trains. At first, railway companies used red to mean stop, white to mean go, and green to mean warn. As you could imagine, trains ran into a few problems with white meaning go. For example, one train mistook a bright star for a white light and something unexpected happened. Because of that, railway companies finally moved green meaning go and used yellow to mean warn. And it's been that way ever since. Red has always been a color that means danger,