Ключевые слова: academic, aged, back, blackboard, board, book, books, chalkboard, class, classroom, college, course, demonstrating, discussing, education, elder, exam, experienced, explaining, graduation, green, high, holding, learn, learning, lecture, lecturer, lesson, man, mentor, mentoring, old, presenting, reading, school, science, secondary, showing, study, studying, suggesting, teacher, teaching, textbook, textbooks, training, tutor, tutoring, university,