機器
activity
blue
business
cement
cobblestone
concrete
construction
conveyor
crusher
dirt
dust
earth
environment
equipment
excavation
excavator
factory
gravel
heap
heavy
hydraulic
industrial
industry
limestone
loading
machinery
manufacturing
material
mine
mineral
mining
operation
outdoors
pit
plant
pollution
processing
production
quarrel
quarry
rock
sand
sky
steel
stone
technology
transport
transportation
work