Ключевые слова: ad, advert, advertisement, advertising, announcement, billboard, black, blackboard, blank, board, business, chalk, chalkboard, class, classroom, clean, colorful, communication, copy, copyspace, drawing, education, element, empty, frame, handwriting, information, learning, lesson, letter, list, message, note, object, old, place, remember, school, space, teacher, text, texture, used, white, write,