Ключевые слова: analyze, coal, construction, engineer, equipment, evaluate, examine, excavation, extract, geological, geologist, hard, hat, helmet, industry, job, labor, leadership, machinery, machinist, mechanical, metal, mine, miner, mineralogy, mining, observation, official, oversee, precious, professional, quarry, safety, subterranean, supervisor, technical, tunnel, underground, worker, workman,