Ключевые слова: background, billboard, black, blackboard, blank, board, chalk, chalkboard, childhood, class, classroom, college, communication, copy, dirty, drawing, education, empty, erase, frame, green, grunge, knowledge, learn, lecture, lesson, message, note, old, remember, reminder, school, space, study, studying, teach, teacher, texture, university, used, wood, wooden, write,