Ключевые слова: academic, adult, blackboard, caucasian, chalkboard, cheerful, classroom, communication, confidence, education, elderly, enthusiastic, experienced, expertise, guidance, happy, inspiration, instruction, intelligence, knowledge, learning, lecturer, lesson, lifestyle, man, mature, mentor, middleaged, physics, positive, professional, professor, school, science, smart, smiling, teaching, tutor, university, wisdom,