英文關鍵字
aluminum
background
bar
bars
building
bundle
chain
chimney
close
coming
construction
couple
cutting
duct
engineering
equipment
factory
focus
grinding
industrial
industry
iron
labor
left
leftn
light
machine
manufacturing
metal
moving
pan
pipe
pipes
pull
right
rod
round
rusty
safety
silver
smoke
spark
steel
tied
tool
warehouse
welding
worker