英文關鍵字
air
atmosphere
black
breakdown
brick
chemical
chimney
climate
coal
contamination
destructive
dioxide
dirty
ecology
energy
environment
factory
fog
fuel
fume
gas
global
heating
industrial
industry
inhaling
manufacture
objects
pipe
plant
pollution
power
refinery
sky
smog
smoke
smokestack
stack
station
steam
technology
tower
toxic
trail
warming