n. 短促的敲打(声);爆震声;敲击声;敲门(或窗等)声
vi. 猛烈敲击;与某物相撞;撞到了桌子
vt. (心)怦怦跳;把…撞击成(某种状态);批评
网络 敲打; 爆震
Knock before you enter.
进来前先敲门。
You don´t have to knock—just walk in.
不必敲门—进来就是了。
I was wakened by a knock at the door.
敲门声把我吵醒了。
They heard a knock at the front door.
他们听到前门有一敲门声。
They were interrupted by a knock at the door.
他们被敲门声打断了。