Ключевые слова: architecture, art, background, black, building, chimney, cloud, clouds, collection, concrete, construction, dark, design, dirty, dust, energy, engineering, environment, factory, filter, fuel, gas, graphic, industrial, industry, large, nature, oil, overcast, place, plant, pollute, pollution, power, production, refinery, shape, sky, smog, smoke, smokestack, steam, symbol, technology, toned, tower, vapor, warming, working,