Linda ,you should have greeted us at the door.语法对吗

Did you have a good time at the party, Linda 翻译：We were greeted at the front door by our host. You should knock at the door before you you _____ the room.【 you should knock at the door before you the room.为什么用enter而不 have you heard someone knock at the door?为什么是knock,不是knoking i saw you cycling when i went to have lunch at the door of d you can have more time. 语法对吗? You __________to lock the door at night. Do you know what should we do at the cinema这句话对吗? Do you have the key _______the door 英文语法问题 I am pleased to hear that you are visiting us at the You should have known me at that