機器
macadam
activity
belt
break
business
cement
cobblestone
complex
concrete
construction
conveyor
crushed
crusher
dirty
dust
ecology
environment
equipment
excavation
extraction
facility
factory
gravel
heap
heavy
industrial
industry
large
limestone
line
machinery
manufacturing
material
metal
mine
mineral
motor
pit
plant
pollution
production
quarry
rock
sand
stack
steel
stone
stonepit
technology