機器
activity
building
bulldozer
business
construction
conveyor
dig
digger
earth
ecology
engineering
environment
equipment
excavation
excavator
extraction
factory
geology
granite
gravel
heap
heavy
hydraulic
industrial
industry
landscape
large
machinery
material
metal
mine
mineral
mover
nature
open
outdoors
pit
quarry
quarrying
rock
shovel
stone
surface
technology
vehicle
white
work
working
yellow