196. When another calling channel/frequency is available，do not use ______ or other safety frequencies to make a transmission.
举一反三
- The Internet is an important channel of learning more information, but many people use it for ______ purpose than to send and receive emails. A: another B: other C: the other D: no other
- 215. When the changing of a VHF channel / frequency is accepted，say _______.
- Which of the following frequencies are not DSC distress and safety frequency? A: 2187.5kHz. 4207.5kHz B: . 6312kHz. 8414.5kHz C: 2182kHz. 829lkHz D: 12577kHz.16804.5kHz
- Analog signals may cause distortion such as graininess or snow in the case of video transmission and static or other background distortion in the case of audio transmission.
- Which of the following is not the possible transmission routes of COVID-19? A: Droplet transmission. B: Contact transmission. C: Arthropod-borne transmission. D: Human-to-human transmission. E: Ocular surface transmission.