英文關鍵字
aluminum
angle
assurance
background
bar
bars
block
building
bunch
check
circles
close
comments
construction
couple
cutting
duct
engineering
equipment
factory
going
grinding
hand
held
hole
industrial
industry
iron
labor
light
liquid
list
machine
making
man
manufacturing
metal
nob
other
pipe
placing
putting
quality
rod
round
safety
side
small
spark
steel
tilt
tool
warehouse
welding
wheel
white
worker