英文關鍵字
area
asset
backdrop
background
barrier
bodyguard
border
building
cage
commercial
construction
control
crime
emergency
fence
fenced
grid
guard
hat
industrial
iron
isolated
link
male
man
mesh
metal
metallic
net
officer
patrol
patrolling
pattern
police
policeman
prevention
prison
protect
protection
safe
safeguard
safety
security
service
shape
steel
surveillance
uniform
wall
watch
wire
work