Ключевые слова: academic, aged, atom, blackboard, board, chalkboard, chemical, chemist, chemistry, class, classroom, college, course, demonstrating, discussing, education, explaining, green, learn, learning, lecture, lecturer, lesson, looking, man, mature, model, molecular, molecule, old, physical, physicist, physics, presenting, research, school, science, scientific, scientist, showing, student, study, studying, teacher, teaching, training, tutor, tutoring, university,