2023년03월11일 16번
[임의 구분] 다음 중 "Radio Waves"를 가장 적절하게 설명한 것은?
- ① General term applied to the use of electromagnetic waves.
- ② Radio determination based on the reception of the direction of a station object.
- ③ Any radiocommunication other than space radio astronomy station
- ④ Electromagnetic waves of frequencies arbitrarily lower than 3,000[GHz], propagated in space without artificial guide.
(정답률: 81%)