Ключевые слова: ad, advert, advertise, announcement, audio, background, billboard, black, blackboard, blog, board, chalk, chalkboard, class, classroom, communication, community, content, drawing, education, frame, future, grunge, knowledge, learn, lesson, marketing, media, message, network, note, remind, school, social, social media, social network, study, studying, teach, texture, used, video, web, web 20, white, write,