英文關鍵字
back
backpacks
caucasian
children
city
closely
coronavirus
couple
covid
disease
education
elementary
epidemic
ethnicity
face
first
friends
healthcare
horizontal
kids
learning
lifestyles
mask
masks
morning
motion
outside
pandemic
people
prevention
primary
protect
protective
quarantine
real
rule
safety
school
schoolboy
schoolgirl
slow
student
study
talking
video
virus
wearing