Ключевые слова: air, atmosphere, blue, building, business, chemical, chimney, coal, construction, contamination, danger, dirty, ecology, emission, energy, engineering, environment, environmental, factory, fuel, gas, global, industrial, landscape, manufacturing, metal, oil, petrochemical, pipe, plant, pollution, power, production, refinery, river, sky, smog, smoke, smokestack, steam, sunset, technology, tower, toxic, warming, water,