英文關鍵字
drainage
rainwater
collector
concrete
pipe
inside
view
architecture
background
bright
channel
circle
concept
corridor
creepy
dark
deep
design
dirty
element
empty
exit
flow
geology
graphic
industrial
light
mystery
passage
path
pattern
perspective
pipeline
plant
pollution
sewage
sewer
sewerage
shine
space
stone
subterranean
texture
tube
tunnel
underground
urban
wall
wastewater
water