Ключевые слова: air, atmosphere, blue, buildings, business, chimney, chimney pipe, chimneys, cityscape, cloud, coal, dirty, ecology, emissions, energy, environment, environmental, factory, gas, global, gray, heavy, industrial, industry, infrastructure, landscape, manufacturing, metal, pipe, pipes, plant, pollution, pollution air, power, production, refinery, sky, smog, smoke, smoking, snow, stacks, steam, steel, technology, tower, toxic, warming, white,