交通灯： 1.交通灯正常状态 a. A红B绿 10秒 b. A红B黄 3秒 c. A绿B红 10秒 d. A黄B红 3秒2.紧急车辆AB道全红3.有车道绿,无车道红-Traffic lights:?. A normal state of a A traffic light red green 10 seconds B B b A red green and yellow three seconds c A B d A yellow-red 10 seconds 3 seconds ?? 2 B red emergency?.?.?. AB Road vehicles all red ?? 3. There lane green, no red lane