鲨鱼（shark）：来源于古英语 "scearc"，意为 "捕食性水生动物"。
例句：
Sharks are one of the most feared creatures in the ocean. (鲨鱼是海洋中最令人害怕的生物之一。)
The great white shark is the largest predatory fish in the ocean. (大白鲨是海洋中最大的捕食性鱼类。)
鲸鱼（whale）：来源于古英语 "hwæl"，意为 "大型海洋动物"。
例句：
Whales are known for their intelpgence and complex social structures. (鲸鱼以其智慧和复杂的社会结构而闻名。)
The humpback whale is known for its beautiful songs and aerial displays. (座头鲸以其美妙的歌曲和空中表演而闻名。)
鳄鱼（crocodile）：来源于希腊语 "crocodilos"，意为 "蜥蜴"。
例句：
Crocodiles are apex predators and can be found in freshwater and saltwater habitats. (鳄鱼是顶级捕食者，可以在淡水和咸水栖息地找到。)
The Nile crocodile is one of the most dangerous animals in Africa. (尼罗鳄是非洲最危险的动物之一。)