单项选择题

Ships at sea are in urgent need of MSI because they are（）various kinds of danger.

A.subject for
B.liable to
C.easy to meet
D.always encounter

点击查看答案&解析

上一题目录下一题

单项选择题

A.NBDP/VHF radio
B.Inmarsat safetyNet/NAVTEX
C.Safety service / Inmarsat-A
D.Long range / short range

单项选择题

A.FEC and ARQ
B.satellite and terrestrial communications
C.radio and telex
D.NBDP

单项选择题

A.by day or at night
B.almost round the clock
C.somewhat and sometime
D.from sunrise to sunset