英文關鍵字
angle
construction
cut
electric
engineering
equipment
factory
grinder
grinding
hand
industrial
industry
iron
machine
man
manufacturing
metal
pipe
power
production
protection
spark
sparks
steel
technology
tool
welding
work
worker
workshop
英文關鍵字
angle
construction
cut
electric
engineering
equipment
factory
grinder
grinding
hand
industrial
industry
iron
machine
man
manufacturing
metal
pipe
power
production
protection
spark
sparks
steel
technology
tool
welding
work
worker
workshop