Please_____on the door before you come in.
问题描述:
Please_____on the door before you come in.
答
knock
knock on敲(门、窗等)
请在你进来前先敲门
答
填 knock
进门前请先敲门
答
knock 祈使句动词原形放句首,敲门
答
knock
具体时态应该用一般时