metamorphic period的用法和樣例：
例句
- It can not only prolong the retention period of flavor, but also avoid flavor metamorphism because of tobacco burning at the high temperature.
因為這一方法既能延長香精的保留期，又能避免煙絲高溫燃燒而使香精變質的缺點。 - The khondalite lithology is composed of a suit of metamorphic aluminium-sedimentary rock.During the Jinning movement, the sedmentary rock experienced four stages of metamorphism.
明確黃陵地區孔茲岩係為一套變質的富鋁質沉積岩組合，在晉寧期造山運動期間該套岩系經歷四期變質作用。
