Ключевые слова: air, atmosphere, background, chemical, chimney, city, climate, cloud, coal, contamination, danger, dioxide, dirty, ecology, emission, energy, environment, environmental, exhaust, factory, fog, fuel, fume, fumes, gas, global, global warming, industrial, industry, manufacturing, pipe, plant, pollution, power, production, sky, smog, smoke, smokestack, station, steam, technology, tower, toxic, warming,