海军陆战队在演习中展示了他们的两栖作战能力。

The ___marines demonstrated their amphibious combat skills during the exercise.

海洋生物多样性对于维持生态平衡至关重要。

___Marine biodiversity is crucial for maintaining ecological balance.

我的表弟刚成为一名海军陆战队员。

My cousin just became a ___Marine.