平静 + 的 + Noun
The adjective 平静 (píngjìng) means "calm," "peaceful," or "tranquil." It can describe a person's emotional state, a voice, or an environment that is free from disturbance. For example, a 平静的回答 is a calm, composed response.
考试结束后,她终于感到内心平静了。
Kǎoshì jiéshù hòu, tā zhōngyú gǎndào nèixīn píngjìng le.
After the exam was over, she finally felt at peace.
湖面非常平静,像一面镜子。
Hú miàn fēicháng píngjìng, xiàng yī miàn jìngzi.
The surface of the lake was very calm, like a mirror.
他用平静的语气回答了所有问题。
Tā yòng píngjìng de yǔqì huídále suǒyǒu wèntí.
He answered all the questions in a calm tone.