Ключевые слова: air, business, carbon, chemical, chimney, climate, cloud, coal, concepts, condensation, damage, day, dioxide, dirty, environment, environmental, exhaust, factory, flue, fog, frame, fuel, fumes, gas, generation, global, health, heavy, industry, issue, layer, manufacturing, mid air, nature, nobody, objects, outdoors, pipe, plant, pollution, power, refinery, sky, smog, smoke, steam, substance, technology, toxic, yellow,