Ключевые слова: art, background, blackboard, board, class, classroom, coach, course, demonstrate, education, educational, emblem, flat, graphics, group, icon, icons, illustration, instruction, isolated, learner, learning, lecture, lecturer, lesson, long, person, pictogram, picture, pointer, presentation, pupil, school, seminar, set, shadow, sign, silhouette, simple, speaker, speech, students, study, symbol, teach, teacher, trainer, training, white,