英文關鍵字
air
background
blue
business
chemical
chimney
climate
cloud
coal
color
construction
cooling
copter
dirty
dust
ecology
electric
electrical
electricity
emissions
energy
environment
factory
fuel
gas
global
industrial
industry
infrastructure
landscape
manufacturing
pipe
plant
pollution
power
refinery
sky
smog
smoke
smokestack
stack
station
steam
steel
technology
tower
toxic
vapor
white