1·I was wakened by a knock at the door.
敲门声把我吵醒了。
—— 《牛津词典》
2·They were interrupted by a knock at the door.
他们被敲门声打断了。
—— 《牛津词典》
3·You're supposed to knock at the door and wait before entering the office.
进办公室之前，你应该先敲门然后等着。
4·There was a knock at the door.
门外传来敲门声。
5·Suddenly there was another knock at the door.
突然，又有人敲门。
6·Just as breakfast was completed there was a knock at the door.
早饭刚吃完，有人敲门。
7·Just when she was going to bed, there was a knock at the door.
正当她要上床睡觉时，有人敲门。
8·Ring the doorbell or knock at the door before you enter the room.
在你进入房间之前，按一下门铃或敲门。
9·No sooner had she fallen asleep than she heard a knock at the door.
她刚睡着就听到了敲门声。
10·Pinocchio went straight to the Fairy's house, firmly resolved to knock at the door.
皮诺乔径直走到仙女家，打定主意要敲门。