英文關鍵字
concrete
conduit
construction
corrosion
culverts
development
dig
ditch
drain
drainage
engineering
equipment
excavation
excavator
foundation
ground
grunge
hole
house
industrial
installation
laying
old
pipe
pipeline
pipes
pit
plumbing
pumping
repair
replacement
sewage
sewer
sewerage
steel
storm
system
technology
trench
tube
underground
water
work