Ключевые слова: background, bituminous, black, central, clean, coal, coal burning, coals, cube, dark, deposits, ecology, effect, energy, environment, exploitation, extract, extraction, fuel, fuels, gas, heat, heating, helmet, hot, industry, lignite, load, loading, manufacturing, material, metallurgical, mine, miner, mineral, mines, mining, nature, pile, power, power station, resources, smoke, stone, things, tools, types, uses of,