Ключевые слова: advertising, arm, background, black, blackboard, blank, board, business, caucasian, chalk, chalkboard, class, classroom, close, communication, concept, copy, drawing, education, elementary, empty, exams, finger, hand, handwriting, hold, holding, horizontal, learn, lesson, message, note, old, people, person, primary, remember, school, space, student, studying, teach, teacher, text, texture, university, white, work, write, writing,