单项选择题
The rules require that a stand-on vessel SHALL take action to avoid collision when she determines that（）.
A.risk of collision exists B.the other vessel will cross ahead of her C.the other vessel is not taking appropriate action D.collision cannot be avoided by the give-way vessel's maneuver alone
单项选择题 The risk of collision shall be deemed to exist if the compass bearing of an approaching vessel （）.
单项选择题 The effectiveness of the action shall be carefully checked until the other vessel is finally （）.
单项选择题 Sailing vessels are stand-on over power-driven vessels except（）.
