Ключевые слова: 5, 50, 50th, abstract, age, asphalt, background, backgrounds, concepts, concrete, count, digit, drawing, fifty, figure, grunge, label, mathematical, measure, natural number, number, numbers, object, old, paint, painted, park, parking, pavement, road, round, serial, shape, sign, space, street, symbol, texture, traffic, transport, transportation, urban, vehicles, yellow, zero,