coal petrography

例句：

1. 1. Coal petrography is a field of study that focuses on the study of coal and its associated rocks.
   煤岩学是一门专注于研究煤炭及其相关岩石的学科。
2. 2. The coal petrography of the region has been studied extensively to understand its geological history.
   该地区的煤岩学研究已经非常广泛，以了解其地质历史。
3. 3.In this area, the coal petrography plays a crucial role in the development of energy infrastructure.
   在这个地区，煤岩学在能源基础设施的发展中起着至关重要的作用。