degree of coal meta-morphism

例句：

1. 1. The study of the degree of coal meta-morphism is crucial for understanding the geological evolution of the region.
   研究煤的变质程度对于理解该地区地质演变至关重要。
2. 2. The degree of coal meta-morphism can vary greatly depending on the type of rock and the conditions under which it wasformed.
   煤的变质程度可以根据岩石类型和形成条件有很大的变化。
3. 3. The degree of coal meta-morphism has been used to determine the age of the rocks in the area, as it reflects changes in the chemical composition over time.
   煤的变质程度被用来测定该地区岩石的年龄，因为它反映了随着时间的推移化学组成的改变。