妖しい
怪しい
building
camera
cctv
circuit
clean
clear
close
closeup
control
corner
defense
electronic
equipment
guard
intelligence
lens
look
modern
monitor
monitoring
nobody
observe
outdoor
private
protect
protection
record
safe
safety
secrecy
secretly
secure
security
see
serene
space
sphere
spy
spying
surveillance
system
technology
television
tv
urban
video
visual
wall
watch