Ключевые слова: abstract, ahead, airport, begin, choice, choose, concept, decision, direction, enforce, feet, first, floor, foot, forbid, government, guide, instruct, instruction, inviting, life, line, mall, man, office, order, pair, path, pavement, people, queue, regulate, regulation, shoe, shoes, sign, stand, standing, start, step, stop, symbol, top, traffic, view, wait, waiting, walk, way, work,