Ключевые слова: background, billboard, black, blackboard, blank, board, box, brush, business, chalk, chalkboard, classroom, color, communication, concept, copy, design, dirty, drawing, educate, education, empty, equipment, frame, green, grunge, information, isolated, label, learn, memo, message, note, notice, office, paper, pattern, remember, reminder, school, sign, single, space, symbol, teach, teacher, texture, white, write, yellow,