機器
3d
airplane
airport
anti
background
baggage
black
boarding
check
clean
control
counter
departure
detect
detector
embassy
entrance
equipment
flight
fly
gate
guard
illustration
inspect
inspection
isolated
metal
monitor
precaution
protection
protective
ray
render
risk
safety
scan
scanner
screening
search
security
steel
system
technology
terminal
through
tourism
transportation
travel
walk