機器
macadam
aggregate
belt
concrete
construction
conveyor
dig
digging
dirt
dredger
dust
earth
engineering
environment
equipment
extraction
factory
fuel
geology
granite
gravel
hard
heap
heavy
industrial
industry
landscape
machinery
manufacturing
material
metal
mine
mineral
motor
ore
outdoors
pebble
pile
quarry
rock
sand
sorting
stack
stock
stone
storage
technology
transport
transportation