All VHF marine band radios operate in the simplex mode，which means that______．
A.only one person may talk at a time
B.only two persons may talk at the same time
C.the radio only transmits
D.the radio only receives
正确答案：A
海上所有的甚高频波段操作在单工模式这意味着在每次仅有一个海员可以交谈
