单项选择题
The line connecting the Loran-C master station with a secondary station is called the（）.
A.Focus line B.Base line C.Side line D.Center line
单项选择题 The information received by AIS will be displayed on（）.
单项选择题 The（）transmits own ship data cyclically via two defined VHF channels and receives the same data of the other ships and objects that are equipped with AIS systems.
单项选择题 Radar makes the most accurate determination of the（）.
