英文關鍵字
air
atmosphere
billowing
billows
blue
breathe
building
chimney
daytime
economy
environment
environmental
exhaust
factory
form
global
high
horizontal
industrial
industry
issues
manufacture
manufacturing
mass
mill
nobody
panoramic
paper
pipe
plant
pollution
production
resolution
sky
smog
smoke
smokestack
stack
steam
warming
white
workplace