Ключевые слова: air, atmosphere, background, beautiful, blue, building, chemical, chimney, clean, cloud, clouds, concept, contamination, design, eco, ecology, energy, environment, exhaust, factory, gas, green, industrial, industry, landscape, leaf, manufacturing, natural, nature, outdoor, peak, plant, pollute, pollution, power, power plant, production, sky, smog, smoke, space, summer, technology, tree, warming, white, wood,