英语翻译The time of day when you feel most energetic is when you

The time of day when you feel most energetic is when your cycle of body temperature is at its peak.
一天中当你感到最有活力的时刻,是在你的体温周期处于高峰的的时候.
The time of day when you feel most energetic （句子的主语,其中when you feel most energetic 是定语从句,修饰the time of day） is (系动词,is 后面的是表语从句)when your cycle of body temperature （表语从句的主语）is （表语从句的系动词）at its peak（表语从句的表语）.
再问： at its peak？这个句子是什么用法？我只知道at home
再答： at its peak, 是介宾短语。peak，高峰。at its peak： 意思是在它的最高点