Ключевые слова: business, coal, crusher, crushing, danger, deep, dig, digger, digging, dirty, dust, earth, ecology, equipment, excavation, excavator, factory, geology, gravel, heavy, industrial, industry, job, machine, machinery, manufacturing, material, metal, mine, mineral, mining, mover, nature, open, pit, pollution, quarry, rock, stone, technology, transportation, work,