英文關鍵字
animation
motion
green
screen
chromakey
book
learning
icon
isolated
simple
black
sign
symbol
object
open
education
illustration
library
literature
dictionary
page
paper
textbook
read
design
element
information
knowledge
shape
studying
school
magazine
background
publication
publish
study
text
encyclopedia
college
novel
pictogram
reader
university
abstract
bookstore
document
pictograph
science
cover
graphic
thin
white