单项选择题
When you doubt the existence of risk of collision,（）.
A.such risk shall be deemed to exist B.such risk shall not be deemed to exist C.you needn't take any action to avoid collision with any vessel D.you should accelerate your speed ahead
单项选择题 When your vessel enters thick fog，she should sound（）every two minutes in accordance with these Rules.
单项选择题 Where does the look-out man stand?（）.
单项选择题 While underway at night you observe a vessel’s range lights in line off your starboard beam． You should（）.
