what shouid we do when the traffic light is red ,yellow or green?

问题描述:

what shouid we do when the traffic light is red ,yellow or green?
意思是啥?那How many lights are there?which side of the road shouid drivers drive on in china?

当路灯为红、黄、绿时,我们应做什么?
那有几盏灯?
在中国,驾驶员应在哪一边开车?