Ключевые слова: background, black, blackboard, board, business, businessman, chalk, chalkboard, class, classroom, communication, concept, design, drawing, education, green, hand, handwriting, handwritten, idea, information, inspiration, isolated, knowledge, learn, learning, lesson, management, marketing, message, motivation, plan, promotion, school, sign, solution, strategy, student, study, success, symbol, teach, text, texture, white, wood, wooden, word, work, write,