flag down

动词 flag down:

1. signal to stop

1. A policeman flagged down the car with his flash light.
   警察挥动闪光灯让那辆车停下。
2. Our car ran out of petrol on the moors but fortunately we were able to flag down a passing motorist who took up to the nearest garage.
   我们的汽车在荒野里没有汽油了，不过幸运的是，我们挥手请一位经过的开车者停下，把我们拉最遑的汽车车修理厂去了。