機器
abundance
blue
brown
building
bulldozer
business
cement
concrete
construction
detail
dig
dredger
dust
factory
formation
geology
granite
gravel
heap
heavy
hill
hydraulic
industrial
industry
machinery
manufacture
material
mine
mineral
mound
mountain
nobody
outdoors
pile
pit
quarry
rock
rough
sand
shovel
site
sky
stack
stacked
stock
stone
surface
texture
work
yellow