Ключевые слова: abstract, art, background, blue, business, car, caution, city, close, color, communication, construction, control, crossroad, design, go, green, icon, intersection, lamp, light, lights, man, metal, nature, road, safe, safety, school, semaphore, sign, signal, sky, spring, street, summer, sun, symbol, technology, texture, traffic, transport, transportation, travel, tree, up, urban, warning, yellow,