英文關鍵字
pollution
environment
dust
smog
asia
protection
city
climate
danger
gas
global
dirty
factory
mouth
safety
serious
virus
business
care
change
smoke
health
air
mask
person
toxic
unhealthy
urban
asian
problem
bad
concept
background
protect
sick
dangerous
haze
face
outdoor
disease
environmental
flu
hazard
medical
trouble
warming
warning
wearing
china
mist
famer
burning
grass
leaves
branches
causing
cause
situation
pm2
farmer
solution