Ключевые слова: air, atmosphere, blue, chemical, chemistry, chimney, city, climate, cloud, contamination, damage, danger, dirty, ecology, emissions, energy, environment, environmental, exhaust, factory, forest, fuel, fume, gas, global, industrial, industry, manufacturing, nature, nobody, outdoors, pipe, plant, pollution, power, sky, smog, smoke, smokestack, steam, technology, toxic, tube, warming, waste, white,