问题补充:
Reportedly on April 15, three people including a Chinese girl were killed in the Boston Marathon attacks when two bombs were , which shocked the whole world.
A. set about
B. set off
C. set up
D. set out
答案:
A. set about
(答案→)B. set off
C. set up
D. set out
解析:考查词组:A. set about出发B. set off引发,引爆C. set up建立D. set out出发,句意:据报道,4月15号,在波斯顿马拉松爆炸案中当炸弹引爆的时候,有三人包括一个中国女孩丧生,这件事震惊了全世界。选B。