英文關鍵字
animated
animation
audience
auditorium
black
blackboard
business
classroom
communication
community
conference
congress
conversation
discussion
education
employee
finance
graphic
icon
information
item
lector
listening
logo
meeting
mic
microphone
motion
online
pack
pictogram
presentation
room
seminar
set
sign
speaker
symbol
teacher
teaching
training
white
worldwide