我需要用钥匙才能打开这个门锁。

I need a key to open this ___lock on the door.

记得把重要文件锁在抽屉里。

Remember to ___lock the important documents in the drawer.

柔道选手用关节技控制住了对手的手臂。

The judo player applied a ___keylock to control his opponent's arm.