Question

Gun control is a subject     Americans have argued for a long time. 

A. of which      B. with which     C. about which      D. into which

Answer 1

C

解析:

句意：槍支控制是美國人爭論了很久的話題。由句意判斷后半句是定語從句，先行詞是Gun control，指物，關系詞在從句中做介詞的賓語，介詞前置，介詞與從句動詞構成搭配argue about sth，選C。