蓝色的大海

blue ___sea

海天一色，美不胜收。

The sky and the ___sea blend seamlessly, a breathtaking sight.

他们在海边建了一座小屋。

They built a cottage by the ___sea.

整个广场上的人群看起来就像一片人海。

The crowd in the square looks like a ___sea of people.