Ключевые слова: academic, adult, aged, background, basic, board, camera, caucasian, class, classroom, college, courses, education, happy, indoors, information, instructor, international, knowledge, learn, lesson, looking, male, marker, mature, pen, person, portrait, profession, professional, professor, qualification, school, senior, smiling, study, teach, teacher, teaching, theme, topic, training, tutor, university, welcome, white, whiteboard, writing,