serene

The mountain lake looked beautiful and serene in the early morning light with no wind to ripple the water.

(Chinese) 清晨阳光下的山间湖泊看起来美丽而宁静，没有一丝风吹起涟漪。

She maintained a serene expression even while dealing with the angry customers at the front desk.

(Chinese) 即使在处理前台愤怒的顾客时，她也保持着安详的神情。