Ключевые слова: air, atmosphere, background, blue, building, business, chemical, chimney, city, climate, cloud, coal, damage, danger, dioxide, dirty, dust, ecology, electricity, emission, energy, environment, environmental, factory, fuel, fume, gas, global, industrial, industry, manufacturing, nature, oil, orange, pipe, plant, pollution, power, silhouette, sky, smog, smoke, smokestack, station, steam, sunset, technology, tower, toxic, warming,