Ключевые слова: abstract, advertising, approve, arrow, background, banner, bind, black, blackboard, blank, blankness, board, business, button, chalk, chalkboard, choice, classroom, click, communication, computer, concept, cursor, design, education, email, enter, exchange, global, homepage, http, icon, information, internet, join, label, lacunae, link, login, login icon, mail, member, message, mouse, net, network, now, offer, on line, open, page, pattern, plank, pointer, push, reflection, register, registration, school, schoolroom, sign, sign up, subscribe, subscription, swap, symbol, tag, teaching, technique, technology, texture, up, user, web, website, white, write, www,