—Thepolicehavebeen

问题详情：

— The police have been ________ the area for quite a long time.

— I've also noticed that. What have they been ________？

A. searching; searching  B. searching for; searching

C. searching; searching for  D. searching for; searching for

【回答】

C

知识点：非谓语动词

题型：选择题