Ключевые слова: background, black, blackboard, board, business, chalk, chalkboard, class, classroom, college, communication, concept, design, drawing, education, empty, frame, hand, handwriting, idea, information, knowledge, learn, learning, lesson, message, people, person, school, sign, space, strategy, student, success, symbol, teach, teacher, teaching, text, texture, to do, university, white, wood, wooden, word, write, writing,