A.HowB.WhatC.WhyD.How about（）is the chain?……

单项选择题（）is designed to send an automatic distress alert when a ship sinks suddenly.

A.Lifeboat
B.A survival craft
C.An EPIRB
D.A SART

单项选择题（）are operated as a secondary method of alerting in the GMDSS.

A.satellite EPIRBs
B.Non-satellite EPIRBs
C.SES and DSC

单项选择题A major advantage of the NAVTEX system when compared to other systems is that（）.

A.the information can be received on an ordinary FM radio
B.warnings are printed out for reading when convenient
C.broadcasts are at scheduled times
D.a low frequency band is used for long distance transmission

单项选择题A Class S EPIRB is a（）.

A.submarine EPIRB
B.safety EPIRB
C.ship EPIRB
D.survival craft EPIRB

单项选择题A Class C EPIRB（）.

A.is primarily designed for vessels operating up to 50 miles offshore or on foreign waters
B.transmits a signal that can be detected by satellite
C.must be manually activated
D.operates in the medium and low frequency bands