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
machine
heavy
connection
corrugated
wire
electric
professional
laying
large
engineering
steel
danger
electrical
cable
corrugation
digging
foundation