Ключевые слова: aged, background, black, blackboard, board, chalk, chalkboard, class, classroom, clock, college, communication, concept, dirty, draw, drawing, educate, education, erase, exam, grunge, information, knowledge, learn, learning, lesson, message, note, old, save, school, sign, start, student, study, studying, surface, symbol, teach, teacher, texture, time, unclean, university, used, vintage, white, write, writing,