英文關鍵字
corrugated
strong
black
pipe
moving
shot
industry
industrial
pipes
piping
vent
factory
duct
tube
tubes
tubing
tunnel
long
closeup
generic
business
manufacturing
draining
large
big
drains
drain
construction
diy
plastic
background
water
liquid
cooling
machinery
machine
building
pump
pumping
ventilation
drainage