Ключевые слова: acid, air, atmosphere, bad, blue, cancer, carbon, change, chemical, chemistry, chimney, clean, climate, cloud, co2, concept, danger, dioxide, dirty, disaster, disease, ecology, effect, emission, emissions, energy, environment, factory, fuel, gas, global, greenhouse, industrial, industry, ozone, pipe, plant, poison, pollution, power, sky, smog, smoke, steam, symbol, technology, toxic, warming, waste, word,