有人在敲门 Someone's Knocking at the Door ; eg.Someone is knocking at the door ; somebody's knocking at the door. i'll answer it

以为有人在敲门 thought i heard a knock

谁在敲门 Who's knocking at the door ; who knocked at the door

机会在敲门 Opportunity Knocks

有人在敲我的门 Somebody's knocking at my door

上帝在敲你的门 God Knocking On Your Door

有人在不停的敲门 Someone keeps knocking

天使在敲我的门 Angel knocking on my door