英文關鍵字
accord
air
boiler
business
carbon
chemical
chimney
cleaning
coal
condensation
control
dioxide
emissions
environment
exploding
facility
factory
feather
fossil
fuel
fumes
furnace
global
hydrocarbons
industry
kyoto
mid
monoxide
nitrogen
oxides
pipe
plant
pollution
scented
sky
smell
smog
smoke
smokestack
stack
steam
substance
toxic
trail
unhygienic
unpleasant
vapor
warming