英文關鍵字
aluminum
automation
metallurgical
business
construction
crane
ecology
energy
engine
engineering
equipment
factory
floor
gears
gray
harmful
heavy
industrial
industry
iron
machine
machinery
manufacture
man
manufacturing
metal
move
mill
chimney
plant
power
processing
production
red
roll
rolling
samara
steel
steam
smoke
technical
technology
tool
worker
workshop
time
lapse
timelapse