单项选择题
A.received alreadly B.have received C.had received D.was receiving
The frequency 156.525MHZ and 156.8MHZ should be used in...
单项选择题The frequency 156.525MHZ and 156.8MHZ should be used in the band of（）.
A.MF B.VHF C.HF D.LF
Actually, the date for entry into effect will be 1st Fe...
单项选择题Actually, the date for entry into effect will be 1st February（）.Though the text does not tell us about it.
A.1995 B.1998 C.1999 D.2000
The（）is that search and rescue authorities ashore, as w...
单项选择题The（）is that search and rescue authorities ashore, as well as shipping in the immediate vicinity of the ship in distress, will be rapidly alerted to a distress incident so they can assist in a coordinated SAR operation with the minimun delay.
A.common communication system B.distress traffic system C.basic concept of GMDSS D.SAR operation procedure
