機器
airborne
aircraft
alien
apparatus
automaton
camera
clandestine
covert
device
drone
espionage
eye
flight
flying
ground
helicopter
hover
illustration
information
intelligence
investigate
landscape
lens
look
mechanical
military
mission
patrol
peer
photograph
propellers
pupil
robot
scout
secret
sky
sneaky
snoop
soar
spotter
spying
stealth
surveillance
survey
undercover
unmanned
vector
weapon