Ключевые слова: adult, black board, board, caucasian, class, classroom, college, computer, concept, discussion, education, formular, group, hand, happy, indoors, learning, lesson, male, meeting, men, modern, people, person, physics, professor, project, school, show hand, smiling, student, students, studying, teacher, teachers, teaching, team, teamwork, technology, training, tutor, university, up, white board, working, young,