题海让大学四年没有难题
白天模式登陆

题目详情

单选题 4, What signal is used to allow a scanning receiver to stop and detect an MF or HF DSC distress message

A. A two-tone alarm code is received

B. A series of four-second dashes are received

C. A 200-bit 100-baud dot pattern is received

D. , A steady audio alarm is received, allowing the operator to select the desired frequencyfor the reception of the message

学科:默认课程

时间:2025-10-26 23:54:46

Copyright © 2022 津ICP备2021001502号