Ключевые слова: adult, attractive, beautiful, caucasian, chalkboard, class, classroom, copy space, education, educational, equation, female, formal wear, formula, glasses, indoors, inside, intelligent, job, knowledge, learn, learning, lecture, lecturer, lesson, looking at camera, mathematical, mathematics, maths, people, person, pointing with finger, profession, professional occupation, professor, showing, study, studying, teacher, teaching, university, woman,