英文關鍵字
alarm
alert
building
business
camcorder
camera
cctv
control
danger
day
device
digital
electronic
equipment
guard
home
indoors
lens
metal
modern
monitoring
observation
observe
observer
office
optical
prevention
privacy
private
protect
protection
record
rotation
safety
secure
security
spy
supervise
surveillance
system
technology
television
video
vision
wall
watching
white