英文關鍵字
crowded
drainage
storm
rain
disaster
weather
motion
concentration
hurricane
waste
plumbing
drain
plant
pipeline
tube
underground
industrial
old
flowing
reflection
roadside
pavement
cover
garbage
urban
water
street
road
city
metal
sewer
manhole
nature
sewage
iron
background
gutter
hole
flood
wet
grate
dirty
steel
river
autumn
environment
natural
gold
maintenance