임의 구분전파전자기능사(구) · 2002년10월06일 · 23/60
23.What does mean?(정답률:알수없음)
1
a large and heavy gun which is fixed to the ground.
2
a small machine which can be carried in the pocket.
3
a signal for help by radio from ship or aircraft.정답
4
a secret word which enables a person to be recognized as a friend.