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