单项选择题
A.hold course and sound a two blast whistle signal
B.hold course and sound no whistle signal
C.change course to the right and sound one blast
D.hold course and sound two prolonged and two short blasts
单项选择题 You are aboard the give-way vessel in a crossing situation．What should you NOT do in obeying the Rules（）.
单项选择题 Which vessel is the stand-on vessel when two vessels crossing in fog are NOT in sight of one another（）.
单项选择题 Which vessel is NOT to be regarded as restricted in her ability to maneuver（）.