英文關鍵字
abstract
aluminum
automobile
automotive
background
business
chrome
circle
circular
closeup
concrete
construction
cutting
design
energy
engine
engineer
engineering
exhaust
factory
fuel
gray
illustration
industrial
industry
iron
line
machine
manufacturing
mechanical
metal
metallic
metalworking
oilindustry
pipe
pipeline
plant
power
production
profile
saw
silencer
stainless
steel
tool
tube
warehouse
work
worker
workshop