海的英语是"sea"。例句：

The sea is vast and deep. (海是广阔而深深的。)

I love the sound of the waves crashing against the shore. (我喜欢海浪拍打岸边的声音。)

We spent the day at the beach, swimming in the sea. (我们在海滩度过了一天，在海里游泳。)