单项选择题
A.COSPAS-SARSAT B.Ground receiving stations C.storing distress signal D.Near-polar orbiting satellites
It is（）for mariners to combine the SART with a float-fr...
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
（）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
