英文關鍵字
air
ancient
big
brown
chimney
closeup
co2
danger
dioxide
dirty
electricity
energy
environment
environmental
factory
fog
gas
generation
global
gloomy
gray
grunge
hot
industrial
industry
large
loop
manufacturing
motion
old
overcast
pairs
pipe
plant
pollution
power
problem
recycle
saving
sky
smog
smokestack
station
steam
technology
tower
vapor
warming
wind