metamorphic period的用法和样例：
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.
因为这一方法既能延长香精的保留期，又能避免烟丝高温燃烧而使香精变质的缺点。 - 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.
明确黄陵地区孔兹岩系为一套变质的富铝质沉积岩组合，在晋宁期造山运动期间该套岩系经历四期变质作用。
