单项选择题
A.magnetic equator B.magnetic longitude reference line C.points where there is no variation D.points where there is no annual change in variation
Solid green arrows on the main body of a pilot chart in...
单项选择题Solid green arrows on the main body of a pilot chart indicate （）.
A.prevailing wind directions B.prevailing ocean current directions C.probable surface current flow D.shortest great circle routes
On the south and the east coasts of Block Island are ci...
单项选择题On the south and the east coasts of Block Island are circles with a dot in the center and labeled CUP. This is a （）.
A.conspicuous object B.steep depression in the surrounding hills that resembles a cup C.domed structure useful for navigation D.calling-up-point used for traffic control
Navigational charts are （） frequent changes，the importa...
单项选择题Navigational charts are （） frequent changes，the important one of which are promulgated by Admiralty Notices to Mariners．
A.published with B.combined with C.in connection with D.subject to
