单项选择题
A.Notices to Mariners B.Mariner's handbook C.Sailing Directions D.Guide to Port Entry
Contour elevations on this chart refer to heights in fe...
单项选择题Contour elevations on this chart refer to heights in feet above mean （）.
A.lower low water B.high water C.low water D.sea level
Navigational charts are subject to frequent changes，the...
单项选择题Navigational charts are subject to frequent changes，the important ones of which are promulgated by （）.
A.Admiralty Notices to Mariners B.Mariner's Handbook C.Catalogue D.Sailing Directions
No navigational aids are shown and the chart is not kep...
单项选择题No navigational aids are shown and the chart is not kept corrected for alterations in depths inside the pecked lines. For more detailed information，the larger scale charts must be （）.
A.referred to B.appreciated C.met with D.concerned
