英文關鍵字
plastic
work
pipeline
trench
construction
line
industry
worker
industrial
ground
field
equipment
earth
technology
tube
underground
dig
excavation
pipe
gas
site
installation
ditch
connect
conduit
communication
cockpit
cabling
electrician
build
engineering
wire
digging
electrical
electric
corrugation
heavy
large
laying
danger
steel
corrugated
professional
cable
foundation
connection
machine