—There is a knock at the door.—---------------?A.who is that?B.who can it be?...—There is a knock at the door.—---------------?A.who is that?B.who can it be?C.who is he?D.do you think who he is?a和c为什么不对啊

one night,they sit down for dinner and there is a knock at the door. —There is a knock at the door.—---------------?A.who is that?B.who can it be?...—There is a knock at the door.—---------------?A.who is that?B.who can it be?C.who is he?D.do you think who he is?a和c为什么不对啊 变为否定句 Jack can drive a car ,too Jack ( )drive a car ,( )变为同义句There is a knock at the door.Someone ( ）（ )at the door. Class Two ____ taking their lessons when there was a knock at the door.为什么A. is B. are C. was D. were 可以说there is a knock at the door吗这里的介词是用at还是用on?knock at和knock on有什么区别呀?P.S.上课时老师讲的是用on,我不太确定,是真的这样吗? knock on;knock at;knock over;knock There was a knock at the door.(改为同义句)_____ ______ ______ the door. He was sleeping when there was a loud knock at the door.[对sleeping提问] The Greens （）（have）supper when there was a knock at the door 动词填空. There was a knock at the door when we () () (have) supper 解释下这句话Knock,knock jokesKnock,knock jokes是现在美国人长说的,原台词是knock,knock,knock,who is there? Listen!There's someone_____(knock)at the door. Listen!There's someone_____(knock)at the door. Class Two___taking their lessons when there was a knock at the door.A.is B.are C.was D.were 答案是D可是这里不是应该把class two当成一个整体吗 There was a loud knock at the door.(用时间状语从句合并成一个句子)She was answering the telephone.There was a loud knock at the door.(用时间状语从句合并成一个句子) then there came a knock at the door接着听到敲门的声音.came能改为followed吗. i think someone is in .let's knock the door 这句话的knock为什么要改成knock at knock on knock into knock at knock up