英文關鍵字
black
board
business
button
calculation
caucasian
class
closeup
coast
college
colorful
compose
congress
education
explain
figure
formula
geometry
gold
hand
indoors
interactive
interview
learning
lecture
lesson
listening
man
math
mathematics
orange
paper
pen
presentation
pupil
school
shape
studying
teach
training
trapezium
triangle
tutor
white
writing