Ключевые слова: academic, adult, audience, business, class, classroom, college, communication, conference, convention, discussion, education, educator, explaining, female, group, happy, indoor, indoors, information, institute, knowledge, learn, lecture, lecturer, man, meeting, multiethnic, people, person, presentation, professional, professor, room, school, science, sitting, smiling, student, study, studying, table, talking, teacher, teaching, training, university, woman, young,