The boy knocked on big double doors and threw them open.

They better keep an eye on her the boys will be knocking down her door in a couple more years!

The boys found the address and knocked on the door.

The boy knocked on the door and was asked who he was.

This time the boy knocked on the corner door and was admitted.

One boy knocked the other boy's tooth out, at least that's what it looked like.

The boy walked into a scenery tree and knocked himself silly.

Your boys will knock at the front door, then take the ground floor.

Armed with these instructions, the boy went round to the back door and knocked.

The boys knocked several tunes at the door, then Joe went to look through a window.