单项选择题
A single line of position combined with a dead-reckoning position results in a(n)（）.
A.estimated position B.assumed position C.fix D.running fix
单项选择题 A single barometric pressure reading of 28.60 indicates（）.
单项选择题 A signal indicating zone time is preceded with the letter（）.
单项选择题 A signal indicating Greenwich mean time would be preceded with（）.
