Ключевые слова: adult, arguing, audience, back, blur, business, businessman, casual, ceiling, chairs, classroom, colleagues, communication, conference, congress, discussion, display, education, event, explaining, group, learning, lecture, light, listening, many, meeting, multimedia, office, participants, people, person, podium, presentation, professor, public, rear, screen, seminar, sit, speaker, speaking, talking, team, training, two, watching, window, woman,