Ключевые слова: background, blue, building, business, chemical, chemistry, chimney, coal, construction, dusk, ecology, electricity, energy, engineering, environment, environmental, equipment, factory, fuel, gas, gasoline, generator, heavy, industrial, industry, manufacturing, metal, oil, petrochemical, petroleum, pipe, pipeline, plant, pollution, power, production, refinery, sky, smog, smoke, station, steam, steel, structure, sunrise, sunset, tank, technology, tower, tube,