1.It took a long time for the baby to quieten down.

1.孩子过了间才停止吵闹。

2.A silencer quietens the noise of the engine.

2.消声器把发机的噪音消弭了。

3.He tried to get in a few digs at you but I quietened him.

3.他本想挖句,但被我劝住了。