機器
macadam
activity
belt
business
coal
cobblestone
concrete
construction
conveyor
crushed
crusher
dig
earth
engineering
equipment
extraction
factory
geology
gravel
ground
heap
heavy
industrial
industrialized
industry
iron
large
loading
lorry
machinery
manufacturing
material
metal
mine
mineral
oredeposit
pebble
pit
quarry
quarrying
rock
sand
stack
steel
stone
technology
transport
transportation
truck