Ключевые слова: black, blacksmithing, carbon, coal, combustion, dirty, earth, energy, energy production, environment, environmental impact, exploitation, extraction, formation, fossil fuel, fuel, gravel, gray, gritty, heat, heating, heavy, heavy industry, industrial, industrialization, mineral deposit, minerals, mining, natural deposits, natural resources, non renewable, pile, pollution, power plant, quarry, raw materials, resource, rocks, sedimentary, stones,