Ключевые слова: abstract, ad, advert, advertisement, advertising, background, billboard, black, blackboard, blank, board, business, chalk, chalkboard, class, classroom, close, closeup, communication, concept, copy, copyspace, design, drawing, education, empty, eraser, frame, handwriting, learning, lesson, message, note, old, school, sign, space, student, surface, symbol, teacher, teaching, text, texture, up, used, white, write,