Ключевые слова: abstract, advertisement, advertising, background, billboard, black, blackboard, blank, board, chalk, chalkboard, class, classroom, close, closeup, communication, copy, dark, design, dirty, distressed, drawing, education, empty, frame, gray, grey, grunge, horizontal, learning, lesson, material, message, nobody, old, photo, retro, rough, school, space, surface, teacher, text, texture, textured, used, vintage, wall, white, write,