The bus driver warned passengers to （）pickpockets.
A、
fight with
B、
guard against
C、
break down
D、
keep an eye on
【正确答案】：B
【题目解析】：
句意：公共汽车司机警告乘客谨防扒手。guard against警戒，符合句意。fight with搏斗；break down失败；keep an eye on照看。
The bus driver warned passengers to （）pickpockets.
The bus driver warned passengers to （）pickpockets.
fight with
guard against
break down
keep an eye on
句意：公共汽车司机警告乘客谨防扒手。guard against警戒，符合句意。fight with搏斗；break down失败；keep an eye on照看。