问题补充:
The staff are excited that they have succeeded in what they to do three months ago.
A. set off
B. set about
C. set out
D. set up
答案:
A. set off
B. set about
(答案→)C. set out
D. set up
解析:考查动词短语:A. set off出发,引爆,引发,B. set about开始,后面接doing,C. set out开始,后面接不定式, D. set up建立,句意:大家很兴奋因为他们成功的完成了3个月前开始做的事情。因为搭配的是不定式,所以选C。