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

单项选择题（）process the distress signal from EPIRB to determine its position and identity.

A.COSPAS-SARSAT
B.Ground receiving stations
C.storing distress signal
D.Near-polar orbiting satellites

单项选择题It is（）for mariners to combine the SART with a float-free satellite EPIRB.

A.essential
B.compulsory
C.optional
D.inadvisable

单项选择题（）is a space system using one or more artificial earth satellites.

A.Satellite network
B.Satellite link
C.GMDSS
D.Satellite system

单项选择题For ships equipped with an SES, it is（）and（）for the operator to send a distress alert.

A.easy/reliable
B.difficult/cheap
C.stable/compulsory
D.easy/expensive

单项选择题In the COSPAS-SARSAT system distress signals are processed by（）and the resulting data are forwarded to（）through（）communication network.

A.MCC/LUT/RCC
B.LUT/MCC/RCC
C.LUT/RCC/MCC
D.LUT/RCC/LUT