As soon as the crew(船员) were attacked, the police to look into the matter.
A. set down
B. set out
C. set about
D. set up
网友回答
A. set down
(答案→)B. set out
C. set about
D. set up
解析：短语辨析。Set down写下，记下；set out to do sth开始做某事；set about doing sth开始丛某事；set up建立，设立，成立；句意：船员们一被攻击，警察就开始调查这起案件根据句意说明B正确。