We knock _____people’s doors, and they usually give us some candy _____ a treat.

题型：不详难度：来源：

We knock _____people’s doors, and they usually give us some candy _____ a treat.
A. on, to           B, at, to           C. on, as           D. on, on

答案

C

解析

考查固定结构。Knock on+window/door,敲门或敲窗户；as作为。我们敲人们的窗户，然后他们给我们糖果作为款待。选C。