英文關鍵字
air
asia
atmosphere
background
boy
building
catastrophe
chemical
chimneys
choke
city
concept
cough
damage
danger
dirty
ecology
energy
environment
factory
gas
gasp
global
guy
health
human
illness
industrial
industry
infection
kid
male
man
mask
mouth
outdoors
people
person
pipes
plant
pollutant
pollution
problem
protect
protection
respirator
smoke
standing
toxic
wear