他咬苹果时下巴发出了咔哒声。

His ___jaws made a clicking sound when he bit into the apple.

机器巨大的金属夹钳看起来像野兽的恐怖大口。

The machine's giant metal clamp looked like the terrifying ___jaws of a beast.

用钳子的夹口把钉子拔出来。

Use the ___jaws of the pliers to pull out the nail.