单项选择题
A.an EGC receiver only
B.a satellite communication system
C.a HF radio system
D.a VHF with DSC system
单项选择题 Please use（）for（）.
单项选择题 Stations in the United States of America are grouped by states arranged in the alphabetical order of their（）.
单项选择题 At least two two-way VHF radiotelephone apparatus shall be provided on every cargo ship of（）tons gross tonnage and upwards but less than 500 tons gross tonnage.