Reportedly yesterday a group of American soldiers were walking along the road in Iraq whe

问题补充：

Reportedly, yesterday a group of American soldiers were walking along the road in Iraq when a bomb was , three of whom were killed.

A. set off

B. set out

C. set up

D. set about

答案：

(答案→)A. set off

B. set out

C. set up

D. set about

解析：短语辨析。A引爆，引起，使发生；B出发；C建立；D出发。结合句意可知A正确。句意：据报道，当一个炸弹被引爆的时候，一群美国士兵正沿着路在行走，三人死亡。