英文關鍵字
activity
arrangement
background
brigadier
building
concrete
consolidation
construction
contemporary
dirt
earth
enhance
equipment
erection
fitting
gravel
grit
ground
hard
hardening
helmet
industrial
industry
job
loam
material
nobody
occupation
orange
outdoor
outdoors
pebble
pit
place
project
road
sand
site
soil
steel
strengthening
urban
work
workplace
yellow