单项选择题 If there’s a fire aboard your vessel, you should first（）.

单项选择题 If two sailing vessels are running free with the wind on the same side, which one must keep clear of the other?（）.

单项选择题 If your weather bulletin shows the center of a low pressure area to be 100 miles due east of your position, what winds can you expect in the northern hemisphere?（）.