Ключевые слова: accept, acceptance, agree, agreement, approval, approve, authorize, authorized, blackboard, board, business, businessman, certified, chalk, chalkboard, check, communicate, communication, concept, contract, control, document, draw, guarantee, happy, i, idea, love, man, message, motivation, note, notice, person, positive, quality, sales, secure, security, service, sign, status, success, text, time, values, verified, verify, word, yes,