機器
arm
background
big
blue
brace
buildingactivity
cable
chain
color
construction
construction site
crane
crawler
danger
day
engineering
equipment
force
hanging
heavy
heavyduty
hoisting
hook
industry
large
machinery
mechanism
metal
moment
nobody
pulley
red
safety
science
sky
stable
steelcable
stretch
tall
tension
tower
track
truss
white