英文關鍵字
anxiety
attention
attitude
book
bored
boredom
boys
campus
caucasian
child
childhood
class
classroom
concentration
daydreaming
depressed
desk
disappointed
down
education
elementary
exhaustion
expression
facial
frustration
girl
headshot
indoors
irritation
kids
learner
listening
looking
only
people
rebellion
sadness
scholar
school
schoolboy
schoolchildren
serious
sitting
stress
stubborn
study
tired
uniform
young
zzz