单项选择题
（）the repeater compass with the master compass，please.
A.Similize B.Clock C.Synchronize D.Position
单项选择题 My gyro-compass error is（）.
单项选择题 There is a possibility that small vessel，ice and other floating objects may not be（）by radar at an adequate range.
单项选择题 Which of the following radar contacts will present the most immediate danger?（）.
