从括号中选择适当的词,并用其适当形式补全短文。 ( i f, until, but, make, at, accidents, be, green, right, red ) This is a street crossing. There are red and green traffic lights ##1## each corner. Drivers must ##2## careful to watch them. When the traffic light is ##3## ,the cars may go. When the light turns ##4## ,the cars must stop. They must wait (等待) ##5## the red light turns green. Then they can go on. Sometimes the drivers want ##6## a right turn or a left turn. They can make a ##7## turn when the light is green or red. ##8## they shou l dn ’ t drive too fast. ##9## they want to make a left turn, they must wait until the traffic light is green. There may be ##10## if drivers don ’ t obey the traffic ru les. All of the drivers should be very careful when they are driving on the road.