Ключевые слова: art, background, black, board, business, class, classroom, coach, communication, course, demonstration, design, education, element, group, growth, icon, icons, illustration, image, isolated, learn, learner, learning, lecture, man, object, people, person, picture, pointer, presentation, professional, professor, school, seminar, sign, simple, speaker, speech, student, study, symbol, teach, teacher, teaching, trainer, training, white,