英文關鍵字
air
atmosphere
bionomics
breath
brume
city
clean
climate
combustion
concept
contamination
dirty
discharge
ecology
environment
evaporation
exhalation
factory
fresh
fume
generate
green
halitus
herb
impurity
industrial
industry
nature
pipe
plant
pollute
pollution
protection
pure
purification
purify
purifying
reek
sky
smog
smoke
smokestack
stack
steam
stink
winter