单项选择题
A.enter the system / contact an RCC
B.access to INMARSAT / establish contact with a CES
C.have absolute priority to enter the system / make contact with a CES
D.enter the system gradually / wait for rescue
单项选择题 It is quite（）for an SES operator to send a distress alert.
单项选择题 In which year was the COSPAS-SARSAT system established?（）
单项选择题 When receiving a distress alert, the SAR authorities ashore and the ships in the vicinity of the ship in distress will（）in a coordinated search and rescue operation with the minimum delay.