英文關鍵字
black
building
business
cam
camera
cctv
ceiling
closeup
control
crime
digital
electric
electrical
electronic
equipment
guard
home
indoor
industry
lens
look
looking
modern
monitor
monitoring
observe
office
privacy
private
protect
protection
record
safe
safety
secrecy
secure
security
spy
supervise
surveillance
system
technology
video
view
wall
watching
white