Ключевые слова: ad, ads, advertisement, background, banner, black, blank, board, business, button, chalk, chalkboard, class, classroom, communication, concept, cyan, design, digital, education, email, empty, flat, frame, handshake, icon, illustration, internet, isolated, letter, mail, marketing, media, new, notification, object, online, promotion, school, sign, social, square, success, symbol, turquoise, web,