Ключевые слова: air, america, american, architecture, atmosphere, background, building, business, california, chemical, city, cityscape, climate, cloud, cloudy, contamination, control, dawn, dioxide, dirt, dirty, district, downtown, dusk, dust, energy, environment, factory, gas, global, industrial, industry, landscape, light, polluted, pollution, pollution air, sky, skyline, skyscraper, smog, smoke, steam, tower, toxic, travel, urban, view, warming,