Ключевые слова: air, atmosphere, background, beautiful, blue, building, chemical, chimney, city, cloud, contamination, day, dirty, ecology, electricity, energy, environment, environmental, evening, factory, gas, global, industrial, lake, landscape, nature, outdoor, pipe, plant, pollution, power, production, reflection, river, sky, smog, smoke, snow, steam, sunrise, sunset, technology, tower, toxic, urban, view, warming, water, weather, winter,