英文關鍵字
acting
adults
audience
back
blur
blurred
blurry
casual
center
class
classroom
community
concept
conference
convention
corporate
defocused
educate
education
event
focus
group
hall
indoors
instructor
large
lecture
lecturer
meeting
modern
people
person
pointing
presentation
professional
public
room
scene
school
seminar
speaker
speech
student
students
teacher
teaching
trainee
training
workshop
young