Since the front door is locked,why not _____at the back door?Someone ,ight come out and answer it.
问题描述：
Since the front door is locked,why not _____at the back door?Someone ,ight come out and answer it.
A.to try knocking B.trying to knock C.to try and knock D.try knocking
答
D
why not do可以具体解释一下吗？固定搭配，为什么不做某事