拳击手的下颌在比赛中受伤了。

The boxer injured his ___mandible during the match.

这只鸟用它的下喙夹住了树枝。

The bird held the twig with its lower ___mandible.

这只甲虫用它的上颚切开了树叶。

The beetle used its ___mandibles to cut through the leaf.