Ключевые слова: abstract, advertising, back, background, billboard, black, blackboard, blank, board, chalk, chalkboard, class, classroom, color, concept, copy, drawing, dust, educate, education, frame, green, hand, horizontal, isolated, learn, lesson, little, message, paris, pattern, presentation, retro, school, slate, smudge, space, studying, teach, vintage, wall, work, write,