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
网友回答
(答案→)A. set off
B. set out
C. set up
D. set about
解析：考查词组;A. set off引发，引爆，出发，B. set out开始，动身，C. set up建立，D. set about出发，句意是：据报道，昨天一群美国士兵沿着伊拉克的公路走，这时炸弹爆发了，有三人丧生。选A。