单项选择题
（）is not a type of IALA maritime buoyage system.
A.special marks B.isolated danger marks C.cardinal marks D.fore and aft marks
单项选择题 When using the anchor to steady the bow while approaching a dock you must be aware of the fact that（）.
单项选择题 When underway and proceeding ahead，as the speed increases，the pivot point tends to（）.
单项选择题 When towing in an open seaway，it is important to use a towing line（）.
