Ключевые слова: air, atmosphere, background, blue, building, carbon, chemistry, chimney, climate, cloud, cloudy, contamination, damage, danger, dioxide, dirty, ecology, energy, environment, environmental, factory, fuel, fumes, gas, global, high, industrial, industry, overcast, pollute, pollution, production, red, sky, smog, smoke, smokestack, stack, steam, technology, three, tower, toxic, trail, vapor, warming, waste,