Ключевые слова: air, background, billowing, blue, chimney, city, cloud, cobalt, cool, district, dream, energy, environment, exhaust, factory, fireplace, flood, freeze, global, heat, horizon, industrial, industry, manufacture, pipe, plain, plant, pollute, pollution, pond, power, production, puff, refine, refinery, reflection, render, ripple, sky, smoke, smokestack, steam, technology, thermal, urban, warming, wave, white, winter,