Ключевые слова: air, atmosphere, backgrounds, blue, building, chemical, chemistry, chimney, climate, cloud, coal, contamination, damage, dioxide, dirty, ecology, emission, emissions, energy, environment, environmental, exhaust, factory, fuel, fume, fumes, gas, global, high, industrial, industry, manufacturing, ozone, pipe, poison, pollution, power, refinery, sky, smog, smoke, smokestack, steam, technology, tower, toxic, vapor, warming, waste, white,