Ключевые слова: academic, ball, balls, blackboard, board, book, books, chalkboard, class, classroom, clicker, college, course, cradle, discussing, education, exam, explaining, graduate, graduation, green, homework, learning, lecture, lecturer, lesson, man, meditating, meditation, mentor, mentoring, newton, pendulum, physicist, physics, reading, rocker, school, student, study, studying, teacher, teaching, textbook, trainee, training, tutor, tutoring, university, young,