Ключевые слова: achievement, advanced, back to school, background, black, blackboard, book, business, chalk, chalkboard, class, classroom, college, community, concept, continuing, continuing education, course, creative, education, hand, icon, illustration, information, isolated, knowledge, learn, learning, lesson, message, motivation, note, professional, refresher, result, school, schooling, sign, study, success, symbol, teacher, teaching, test, text, training, university, white, white background, words,