Ключевые слова: abstract, adult, age, audience, auditorium, blur, blurred, boardroom, business, busy, classroom, concept, conference, connection, corporate, crowd, education, group, hand, knowledge, large, learning, lecture, lesson, meeting, men, movie screen, note, online, people, person, presentation, public, room, school, seminar, sit, speaker, speaking, students, study, teacher, teaching, technology, teenage, training, tutor, university, white, young,