改错.Knock before you enter into the room.

改错.Knock before you enter into the room. you should knock at the door before you the room.为什么用enter而不 please knock at the door before you enter the room（同义句转换） Please knock at the door before you enter the room .(同义句转化)) ——at the door before you enter my room A knock B knocking Ck ______ at the door before you enter my room, please. A．Knock 同义句转换Please knock at the door before you go into the room you must ____(knock)on the door before you enter always knock on the door before you enter Before you_____(enter)the office,you should______(knock)at t Don't enter into the room before they tell you to do that.修改 ______ at the door before you enter my room,please.