英文關鍵字
drain
drainage
rainwater
drainpipe
rain
trench
water
tube
gutter
cover
stone
europe
ground
system
gravel
pipeline
sewage
pipe
insulation
surface
sewer
outdoor
sewerage
waterproofing
downspout
stormwater
ditch
outside
downpipe
snow
mountains
grass
supply
industrial
infrastructure
engineering
technology
maintenance
line
industry
storage
connection
equipment