英文關鍵字
abstract
airplane
and
background
blackboard
board
business
caravan
chalk
chalkboard
city
class
classroom
college
color
copy
dark
design
dirty
education
empty
flying
heavy
knowledge
lesson
light
material
message
mist
nature
nobody
ocean
outdoors
pattern
people
rain
school
sign
space
study
symbol
teacher
teaching
text
texture
time
trucks
university
word
writing