coal mine
noun [ C ] uk/ˈkəʊl ˌmaɪn/ us/ˈkoʊl ˌmaɪn/
煤矿
the deep hole or system of holes under the ground from which coal is removed
coal mining
noun [ U ] ukus
煤矿业，开采煤矿（的工作或过程）
the business, job, or process of removing coal from the ground