题目内容：

He knocked ___an old man and knocked him ___ .A.into,into B.into,down C.down,on D.at on
He knocked ___an old man and knocked him ___ .
A.into,into
B.into,down
C.down,on
D.at on

优质解答

knock into 撞上（某人）；knock at 敲（门、窗等）；knock down 击倒,撞倒；杀(价),降(价)；拆除；knock on 敲(门、窗等所以选B,他撞上一位老人并且把他撞倒了.不懂追问,