____ at the door before entering,pleaseA.knocked B.To knockC.KnockingD.Knockchoose?why?祈使句就能说明选D？

Someone is knocking at the door.____ is it? Please ____(knock)at the door when you come in. What where you doing when someone Knocked at the door?I ____ ____ ____ ____ ____(接电话) Listen,l hear someone knocking at the door的同义句Listen,____ _____ a knock on the door Look!He is looking out______ the door ____ the birdof和at 应该各填哪个? the door is ____(close) Wolf At The Door 歌词 knock at the door造句 Wendys at the classroom door . no cover at the door at the door 的意思 at the dear's door --who's that at the door?--____ is a postman.A.she B.thisC.itD.he -Who's knocking at the door?- ____ me Tom.It's That's哪个呢? someone is knocking at the door,____ _____?如何变反义疑问句为什么 arent they Who's it ____ the door?(A.on;B.down;C.at;D,in)说出为什么 at the front door和at front door的区别 the ____ is not for the door.