英文關鍵字
activity
building
cement
concrete
concreting
construction
contractor
electric
equipment
floor
flowing
frame
gravel
gray
industry
installing
issues
loading
manual
men
messy
mixer
mixing
occupation
people
pipe
pouring
repairing
restoring
rock
rod
site
social
spreading
stability
stone
strength
support
trowel
uniform
wet
worker
working