i think someone is in .let's knock the door 这句话的knock为什么要改成k

have you heard someone knock at the door?为什么是knock,不是knoking Listen:Someone ______(knock) at the door. knock at the door WHEN I WAS READING I HEARD SOMEONE -----(KNOCK)AT THE DOOR I heard someone _____(knock /knocking) at the door just now i __(read) a history book when someone __(knock) at the door can you hear someone _____(knock) on the door now Did you hear someone knock at the door knock at the door造句 关于knock at the door. We make it a rule to knock at the door before you come in.I 改错1.Is your watch made from gold?2.A knock at the door was i