Ключевые слова: 1, 2, 3, 4, 5, action, advance, advancement, begin, count, five, four, headway, improvement, itemize, items, list, number, numeral, numeric, one, pathway, phase, plan, point, priority, procedure, proceed, progress, progression, progressive, route, series, set, stages, start, step, step by step, steps, success, three, time, timer, to do, track, two, way,