英文關鍵字
air
atmosphere
backlighting
chemical
chimney
climate
cloud
construction
danger
dioxide
dirty
ecology
emission
energy
environment
environmental
exhaust
factory
fog
fume
gas
global
industrial
industry
manufacturing
nature
nobody
outdoor
pipe
plant
pollution
power
production
refinery
silhouette
sky
smog
smoke
smokestack
stack
steam
technology
tower
toxic
tube
vapor
warming