Ключевые слова: ad, advert, advertisement, advertising, background, billboard, black, blackboard, blank, board, business, chalk, chalkboard, class, classroom, close, college, communication, concept, continuing, copy, copyspace, drawing, education, empty, frame, grunge, handwriting, isolated, learn, lesson, message, note, old, retro, school, sign, space, student, symbol, teach, teacher, text, texture, university, used, white, write,