marine

我的表弟刚成为一名海军陆战队员。

My cousin just became a ___Marine.

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.

这位教授专门研究海洋生物学，专注于海洋生态系统。

The professor specializes in ___marine biology, focusing on oceanic ecosystems.