single coal的用法和樣例：
例句
- The combustion characteristic of macerals from four types of coal are investigated by means of thermogravimetry.
本文用熱天平研究了四種煤的顯微組分富集物的燃燒特性。 - Two raw coals from Yueliangtian and Kaili coal mines in Guizhou Province were extracted with dichloromethane separately.
摘要用二氯甲烷對貴州月亮田和凱里兩種煤樣進行了索氏萃取，並採用柱色譜對萃取物進行了族組分分離。
