Ключевые слова: adults, attention, audience, auditorium, back view, blank, board, business, business conference, business meeting, business seminar, businessman, conference, congress, copy space, corporate, corporate business, crowded, dark, education, event, group, guidance, hall, head, indoor, indoors, job, lecture, listeners, loudspeaker, many, meeting, men, participants, people, presentation, professional, public, seats, seminar, silhouette, sitting, speech, summit, viewer, white, work,