英文關鍵字
three
people
mature
adult
woman
female
caucasian
child
boy
male
black
animation
education
school
icon
diverse
recycling
classroom
global
learning
elementary
concept
digitally
generated
video
study
student
symbol
knowledge
sign
college
university
class
studying
illustration
digital
design
graphic
lesson
learn
business
vector
technology
web
internet