Ключевые слова: advert, advertisement, assistance, background, billboard, blank, board, business, chalkboard, class, communication, concept, confusion, copy, education, empty, faq, grungeblackboard, handwriting, help, holding, icon, information, learning, mark, message, note, note paper, notepaper, paper, primary, problem, push pin, question, school, sign, solution, space, student, symbol, teacher, teaching, text, white, write,