英文關鍵字
building
cable
camcorder
camera
cctv
closed
computer
control
danger
detection
electric
electrical
electronic
equipment
guard
home
house
infrared
isolated
lens
look
monitor
observe
outdoors
pole
police
privacy
private
protect
protection
record
safety
secrecy
secure
security
spy
street
surveillance
system
technology
television
traffic
urban
video
view
wall
watches
webcam
white