The top of the horn was a little metal cap.

喇叭的顶部是一个小金属帽。

I tore the metal cap off the bottle and poured him a stiff drink and a light one for myself.

我撕下瓶子的金属盖， 给他倒了一杯烈性饮料， 也给自己倒了一杯清淡的。