air
architecture
blue
brick
chimney
coal
condensation
cool
cooling
cylindrical
electric
electrical
electricity
energy
environment
environmental
evaporation
factory
fuel
gas
generate
generating
generator
heat
heaven
industrial
industry
lamp
leaves
morning
mountain
nuclear
plant
pollute
pollution
round
sky
smog
smoke
stack
station
steam
tower
tree
tube
turbine
vapor
water