英文關鍵字
abstract
anti
background
barbed
barrier
blue
border
closed
crime
criminal
danger
day
defense
fence
forbidden
freedom
grid
guard
helix
industrial
industry
law
metal
person
politics
prevent
prison
private
restrict
security
sharp
sky
spikes
status
steel
terror
terrorist
thorn
top
violence
wall
war
white
wire
zone