Ключевые слова: attendance, audience, back, business, businessman, camera, coaching, conference, congress, convention, corporate, crowd, discussion, education, event, forum, full, group, hall, hand, head, information, knowledge, learn, lecture, lecturer, listeners, live, man, manager, meeting, mobile, participants, people, phone, photo, presentation, room, science, seminar, sitting, smartphone, speaker, streaming, teaching, training, university, video, workshop,