機器
activity
belt
blue
bulldozer
coal
construction
conveyer
conveyer belt
conveyor
crushed
crusher
danger
dig
dirt
earth
energy
equipment
excavation
excavator
extraction
geology
gravel
heap
heavy
industrial
industry
large
limestone
loader
machinery
manufacturing
material
mine
mineral
ore
pit
plant
power
precious
production
rock
sand
stone
surface mining
transport
transportation
work