Ключевые слова: 247, app, black, book, brain, certificate, chat, computer, concept, design, diploma, dollar, education, flat, global, graduation, hashtag, hat, icon, illustration, internet, isolated, knowledge, laptop, line, magnifying glass, money, online, outline, people, play, research, search, share, silhouette, simple, smartphone, social network, sticker, tablet, teacher, thin, touchscreen, video, web, wifi, world,