在什么情况下向右转时必须开启右转向灯?When must you signal that you are turning to the right?
只有在对面或者后面有其他车的时候才需要打转向灯Only if other traffic is approaching or following you
总是需要打灯,并且在转向前至少提前两秒钟打灯Always, and for at least two seconds before you turn
总是需要打灯,并且在转向前至少提前三秒钟打灯Always, and for at least three seconds before you turn