please knock at the door before you enter the room（同义句转换）please knock at the door _________ __________the rooom

Please ____(knock)at the door when you come in. knock at the door before entering please句中只有KNOCK AT 一个动词?enter为什么不是? knock at,knock onWhat's the differance? please knock at the door before you enter the room（同义句转换）please knock at the door _________ __________the rooom knock at the door造句 Please knock at the door before coming i____the meeting room.横线上填什么单词 knock at the door before entering please这句话是时间状语从句吗?那句中只有KNOCK AT 一个动词?enter不是？ knock on;knock at;knock over;knock Listen:Someone ______(knock) at the door. 关于knock at the door.为什么不是knock the door? at表示什么? knock at the door敲门应该是knock at the door,有时也看到有用knock on the door的,还有是不是可以直接说“knock the door呢? Would you please ____________(not knock)on the door? 英语改错 “Please knock the door before entering.” knock at the door 和 knock on the door有什么区别吗详解,谢 knock at the door和knock on the door到底有什么区别? knock on knock into knock at knock up i think someone is in .let's knock the door 这句话的knock为什么要改成knock at 1、With the help of the PLA men ,my mother was saved.（改写句子,句意不变）________ ________ the PLA men,my mother was saved.2、Please knock at the door before you enter the room.（同义句转换）Please knock at the door ________ _____