在这个宁静的湖泊旁，人们可以享受大自然。

People can enjoy nature by this ___tranquil lake.

湖面在月光下显得格外宁静。

The lake looked especially ___tranquil under the moonlight.

湖边的小屋是一个宁静的避风港。

The cabin by the lake is a ___tranquil haven.