单项选择题
The GMDSS is a world-wide communication network combining（）with（）.
A.satellite /terrestrial system B.INMAARSAT/COSPAS-SARSAT C.SART / EPIRB D.geostationary/polar-orbiting satellites
单项选择题 The general benefit of the GMDSS is to（）.
单项选择题 By using previous communication system, rescue is often a matter of chance. What does “a matter of chance” mean?（）
单项选择题 We（）a sharp lookout while sailing in the iced waters.
