adult

attention

boys

caucasian

childhood

children

class

classmates

classroom

colledge

communication

concentrating

connection

day

desk

digital

education

elementary

girl

girls

group

indoors

kids

knowledge

korean

learning

lesson

modern

network

people

primary

pupils

school

schoolboys

schoolchildren

schoolgirls

sitting

smiling

student

tablet

teacher

teaching

technology

together

working

young