Ключевые слова: background, business, circle, class, color, colorful, computer, concept, contour, design, education, elearning, flat, graduation, hour, icon, illustration, internet, isolated, knowledge, learning, lecture, lesson, line, linear, minute, modern, object, online, outline, pointer, school, set, sign, student, study, symbol, teacher, technology, time, timer, training, video, watch, web, webinar,