Ключевые слова: adult, audience, auditorium, back, blur, business, businessman, casual, chairs, colleagues, conference, congress, convention, discussion, display, education, event, explaining, female, group, hall, indoors, learning, lecture, listening, many, meeting, men, multimedia, office, participants, people, person, podium, presentation, professor, projector, public, rear, rear view, room, screen, seminar, sit, speaker, speaking, team, training, view, watching,