機器
asphalt
broom
brush
building
car
cartoon
city
clean
cleaner
cleaning
cleanliness
cleanup
company
container
dirt
driving
dust
emergency
environment
floor
garbage
icon
industry
lorry
maintenance
municipal
recycling
refuse
road
sanitation
side
sidewalk
street
sweeper
sweeping
town
tractor
trash
truck
urban
vacuum
vehicle
washer
waste
wheel