英文關鍵字
air
blue
building
business
carbon
chemical
chimney
city
climate
cloud
coal
construction
copter
dioxide
dirty
ecology
electric
energy
environment
environmental
exhaust
factory
fuel
gas
global
heavy
industrial
industry
infrastructure
large
oil
pipe
plant
pollution
power
sky
smog
smoke
spewing
stack
station
steam
steel
structure
technology
tower
toxic
warming
waste
white