please tell me if he knocks()the door.A.at B.in C.with D.by

问题描述:

please tell me if he knocks()the door.A.at B.in C.with D.by

A knock at the door敲门.=knock on the door吗?行,因为在课本上这两个介词at和on都出现过。都可以和knock连用,表示“敲门/窗”。