Ключевые слова: air, atmosphere, cartoon, chimney, city, climate, cloud, contamination, damage, danger, dioxide, dirty, dust, ecology, energy, environment, factory, fog, fume, gas, global, haze, health, industrial, industry, nature, outdoor, pipe, plant, pollute, pollution, power, problem, protection, sky, smog, smoke, station, steam, toned, toxic, urban, warming,