Reportedly on April 15, 2013 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
网友回答
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，2013年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。