Ключевые слова: air, brown, chemical, chimney, co2, coal, damage, danger, day, dioxide, dirty, electricity, energy, environment, environmental, factory, fog, fuel, fumes, gas, generation, geo, global, grunge, hot, industrial, industry, large, manufacturing, nature, pipe, plant, pollution, power, problem, refinery, risk, safety, saving, sky, smog, smoke, space, station, steam, steel, sun, technology, tower, warming,