51According to SMCP,In shore-to-ship and ship-to-shore communica
2023-12-01广-掌握-多002
51According to SMCP,In shore-to-ship and ship-to-shore communication or radio communication in general, which Message Markers may be used. （ ）.
A.INSTRUCTION
B.MESSAGE
C.REQUIRE
D.WARNING
正确答案是AD
