英文關鍵字
background
barb
barbed
barbwire
barrier
blue
border
boundary
camp
crime
criminal
danger
escape
fence
forbidden
freedom
gate
guard
iron
isolation
jail
line
metal
military
nobody
penitentiary
police
prevent
prison
prisoner
private
protection
razor
refugee
safety
secure
security
sharp
sign
silhouette
sky
steel
sun
wall
war
wire