acting
adult
audience
back
blur
business
businessman
caucasian
chair
conference
congress
display
education
equipment
event
group
hall
head
information
instructor
learning
lecture
man
mature
meeting
orator
participants
people
person
podium
presentation
public
rear
room
screen
seat
seminar
shoulder
speaker
student
teaching
training
unrecognizable
view
work
workforce
workshop