英文關鍵字
analyze
analyzing
blackboard
boy
chemical
chemist
chemistry
child
childhood
class
classroom
clever
close
closeup
compare
data
education
experiment
flask
fluid
formula
head
kid
knowledge
lab
laboratory
learn
learning
lesson
liquid
little
negative
observing
reaction
red
research
school
schoolboy
science
scientific
scientist
scratching
smart
student
study
studying
substance
up
wrong