珊瑚礁为许多海洋生物提供了栖息地。

The coral reef provides a habitat for many ___marine creatures.

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.

他叔叔是一名海军陆战队员，曾在多个国家服役。

His uncle is a ___Marine who has served in several countries.