英语改错 “Please knock the door before entering.”

英语改错 “Please knock the door before entering.” knock at the door before entering please句中只有KNOCK AT 一个动词?en knock at the door before entering please这句话是时间状语从句吗? ____ at the door before entering,please We should k____at the door before entering. 几道简单的英语改句子please knock at the door before you come into the 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)) Please knock on the door before you go to the office 同义句 同义句转换Please knock at the door before you go into the room Please knock on the door before _into the Office.进办公室前请敲门 翻译 ______ at the door before you enter my room, please. A．Knock