Ключевые слова: blackboard, board, chalk, chalkboard, childhood, class, classroom, clips, closeup, college, crayons, data, desk, different, dirty, draw, drawing, education, elementary, green, isolated, learn, lesson, many, multicolored, nobody, notebook, object, office, open, orange, school, skill, small, space, stack, supplies, teach, teaching, text, textbook, university, vacations, various, wall, white, wisdom, write, writing,