“红灯停,绿灯行。”汽车遇到交通监管红灯就要停下来,不能闯红灯;行人过十字交叉路口时要观看红绿灯指示,绿灯亮,行人通行,这是交通安全规则。修马路的地方,一到晚上点上红灯,以便引起人们的注意,电影院的安全门上,电信铁塔上也都用红灯作危险信号等等,这是不是因为红灯鲜艳醒目的缘故呢?同学们在用三棱镜探究太阳光(白光)的奥 “The red light stops and the green light goes.” The car will stop when it encounters traffic lights. It cannot stop at a red light. When a pedestrian crosses a crossroads, it must watch the traffic lights, and the green light indicates pedestrian traffic. This is the traffic safety rule. On the road to repairing the street, a red light is illuminated at night to attract people’s attention. The red light is also used as a danger signal on the security gate of the cinema and on the telecommunication tower. Is this because of the bright red light? Students are using prisms to explore the sun (white light)