機器
backhoe
big
building
bulldozer
business
cliff
construction
dig
dirt
dust
earth
ecology
engineering
environment
equipment
excavation
exploration
extraction
factory
geology
granite
gravel
ground
heavy
industry
landscape
large
limestone
marble
material
mine
mineral
mining
nature
open
ore
outdoor
pit
production
quarry
rock
sand
stone
technology
transportation
truck
vehicle
work
yellow