英文關鍵字
aluminum
automation
metallurgical
business
construction
ecology
energy
engine
engineering
equipment
factory
floor
gears
gray
harmful
helmet
heavy
industrial
iron
machine
men
man
machinery
manufacture
metal
mill
panel
people
plant
rotate
power
processing
production
roller
rolling
samara
steel
steam
technical
technology
tool
wind
work
worker
workshop
time
lapse
timelapse