Ключевые слова: abstract, advantage, apparatus, background, buy, candy, choice, choose, competitive, dark, eating, food, front, generic, glass, gray, helix, item, line, machine, market, marketing, no, nobody, nothing, numbers, objects, office, option, pan, products, proposition, public, row, select, selection, sell, shelf, special, spiral, style, technology, tray, unique, unit, unusual, vending, white, window,