adult
advice
audience
back
backs
blur
business
business conference
businessman
casual
ceiling
chairs
charts
classroom
colleagues
conference
congress
discussion
display
education
event
explaining
focus on foreground
group
group of people
hall
indoors
learning
lecture
listening
many
meeting
multimedia
participants
pass
people
person
podium
presentation
professor
public
rear
rear view
screen
seminar
speaker
speaking
team
training
view