It suddenly to the detective that the professor was probably murdered by his own wife .
A. came about
B. took place
C. happened
D. occurred
网友回答
A. came about
B. took place
C. happened
(答案→)D. occurred
解析：考查词组：这几个词都有发生的意思，但只有D. occurred可以用于It occurred to sb that…某人突然想起…，句意：侦探突然想起教授有可能被他自己的妻子谋杀了。选D。