英文關鍵字
air
billowing
black
carbon
carcinogen
change
chimney
city
clean
climate
cloud
co2
coal
color
construction
dark
dioxide
dust
ecology
emission
environment
environmental
epa
factory
fog
gas
gasses
greenhouse
harmful
hazardous
health
highlight
industrial
industry
orange
ozone
pipe
plant
pollution
power
silhouette
site
smog
smoke
smokestack
stack
sunset
urban
waste