metamorphic grade of coal的用法和樣例：
例句
- These findings are significant in understanding of the characteristics of coal petrographic constituents and in separating and enr.
煤巖組分和煤變質(zhì)程度是影響煤層生儲氣能力的主控因素。 - Research shows that maceral and the degree of metamorphism of coal rock are key factors that control the generating and storing capacity of coal rock.
煤巖組分和煤變質(zhì)程度是影響煤層生儲氣能力的主控因素。
