機器
activity
building
bulldozer
business
construction
conveyor
development
dig
dirt
dump
dust
earth
engineering
environment
equipment
excavator
extraction
factory
gear
gravel
ground
growth
heap
heavy
hydraulic
industrial
industry
iron
large
machinery
material
metal
mine
mineral
mining
mover
outdoor
quarry
rock
rubble
steel
stone
technology
track
transportation
truck
vehicle
work
working