英文關鍵字
appliance
atmosphere
building
business
cargo
chemical
chimney
coal
color
concepts
construction
diesel
dust
energy
engine
factory
flue
form
heat
heavy
high
illuminated
industrial
industry
iron
ironworks
locomotive
machinery
metal
metallurgical
outdoors
pipe
pipes
plant
pollution
power
railroad
sinter
smog
smoke
sparks
steam
steel
sunset
temperature
toxic
track
transportation
vanishing