英文關鍵字
access
air
airfield
airport
area
barb
barbed
barbwire
barrier
base
blue
boundary
camp
captivity
chain
close
compound
convict
crime
criminal
danger
defence
defense
escape
fence
for
forbidden
guard
hedge
imprison
jail
limitation
link
measure
military
net
netting
network
prison
private
property
protected
protecting
protection
razor
restricted
safety
secure
security
sky
steel
sunny
taken
under
wall
wire
wired