英文關鍵字
backpack
backpacks
boy
child
coronavirus
covid
covid19
danger
dangerous
education
epidemic
europe
face
freedom
friends
friendship
girl
infection
kids
mask
masked
medical
noncontact
outdoor
outdoors
outside
pandemic
people
portrait
protection
pupils
quarantine
safety
school
schoolboy
schoolchildren
schoolgirl
students
together
virus