英文關鍵字
asphalt
city
collector
damaged
danger
deep
detail
dilapidated
dirty
drain
drainage
fenced
flow
gray
hatch
hole
hose
industry
infrastructure
lid
manhole
metal
old
open
pollution
pumped
pumping
redwhite
ribbon
road
round
sewage
sewer
sewerage
sleeve
sleeves
stick
street
system
tape
that
triangle
tube
two
urban
which