機器
accident
architecture
broom
brush
car
chic
city
clean
cleaner
cop
day
dirt
dirt removal
dirty
employment
equipment
flow
grime
industrial
job
machinery
male
man
municipal
municipal officials
oil
pavement
prevent accidental
professional
recycling
residential
road
sanitation
service
sidewalk
spray
stains
surface
sweeper
sweeping
technology
tool
track
transport
wash
washing
waste
water
work