英文關鍵字
abstract
activity
backgrounds
brick
building
built
bundle
business
cement
chrome
circle
concepts
concrete
construction
cylinder
dimensional
engineering
equipment
floor
frame
group
ideas
industry
iron
light
manual
material
men
metal
metallic
objects
occupation
part
people
pipe
pipeline
pouring
rod
rough
rusty
site
stack
steel
strength
structure
technology
three
tube
wall
worker
working