单项选择题
A.essential B.compulsory C.optional D.inadvisable
（）is a space system using one or more artificial earth ...
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
For ships equipped with an SES, it is（）and（）for the ope...
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
In the COSPAS-SARSAT system distress signals are proces...
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
