Ключевые слова: air, air pollution, area, backgrounds, ban, bomb, book, carbon, carbon dioxide, cartoon, city, clean, co 2, co2 emission, comic, comic book, comics, dioxide, do not, driving, emissions, engine, environment, environmental protection, exhaust, forbidden, graphics, half tone, icon, illustration, law, logo, message, not allowed, pattern, pop art, prohibited, prohibition, protect, protection, reduction, restricted, restriction, retro, road, sign, symbol, zone,