Ключевые слова: air, atmosphere, backdrop, background, building, business, chemical, chimney, city, cityscape, conditioning, danger, dirt, dirty, district, duct, dust, ecology, emissions, energy, exhaust, fog, fume, futuristic, harmful, haze, health, house, industry, landmark, maintenance, modern, nature, polluted, repair, sky, skyline, skyscraper, smog, smoke, street, technician, technology, town, traffic, unhealthy, urban, vent, ventilation, wall,