英文關鍵字
belt
blue
bottle
coal
conveyor
danger
design
dirt
earth
energy
equipment
excavation
factory
geology
giant
glass
gold
goldmine
ground
heavy
huge
indoors
industrial
industry
interior
large
line
long
machine
machinery
manufacture
manufacturing
metal
mine
minerals
modern
motion
ore
outcrop
plant
power
precious
production
rock
sand
soil
strip
transport
vehicle
work