Ключевые слова: 20, 80, abstract, background, business, cause, chart, compare, concept, contrast, design, diagram, discount, drawing, economy, education, effect, efficiency, eighty, finance, graph, idea, illustration, law, letter, majority, management, mark, message, metaphor, note, percent, percentage, performance, price, principle, productivity, profit, result, rule, scale, sign, symbol, twenty, word,