英文關鍵字
activity
builder
building
construction
equipment
ground
industrial
industry
man
repair
road
shovel
site
work
worker
contractor
dig
dirt
earth
engineering
excavation
machine
sand
street
tool
clay
danger
dirty
drainage
foundation
hole
labor
outdoor
outside
pipe
pipeline
pipes
piping
plumbing
replacement
sewage
sewerage
soil
supply
trench
underground
utilities
utility
water