（） is not required by bridge-to-bridge commun

（）is an area within the radiotelephone coverage of at l...

单项选择题（）is an area within the radiotelephone coverage of at least one VHF coast station in which continuous Digital Selective Calling is available.

A.Sea Area A1
B.Sea Area A2
C.Sea Area A3
D.Sea Area A4

What is the basic concept of GMDSS? （）A.Search and resc...

单项选择题What is the basic concept of GMDSS? （）

A.Search and rescue authorities ashore can be alerted to a distress situation
B.Shipping in the immediate vicinity of a ship in distress will be rapidly alerted
C.Shoreside authorities and vessels can assist in a coordinated SAR operation with minimum delay
D.All of the above

What is the action that a GMDSS Radio Operator should t...

单项选择题What is the action that a GMDSS Radio Operator should take when a DSC distress alert is received? （）

A.No action is necessary，as the DSC control unit will automatically switch to the NBDP follow-on communications frequency
B.The operator should immediately set continuous watch on the radiotelephone frequency that is associated with the frequency band on which the distress alert was received
C.The Operator should immediately set continuous watch on VHF channel 70
D.The Operator should immediately set continuous watch on the NBDP frequency that is associated with the frequency band on which the distress alert was received

GMDSS

（） is not required by bridge-to-bridge communications.