It was not until he came back he knew the police were looking for him.A. whichB. sinceC.

问题补充：

It was not until he came back he knew the police were looking for him.

A. which

B. since

C. that

D. before

答案：

A. which

B. since

(答案→)C. that

D. before

解析：考查强调句型 it is +被强调部分+that …。句意：直到他回来他才知道警察一直在找他。