单项选择题
A.Supplements B.Annual Summary C.Navigational Warnings D.Notices to Mariners
On the high seas，a fog signal consisting of one prolong...
单项选择题On the high seas，a fog signal consisting of one prolonged blast followed by four short blasts would indicate the presence of a（）.
A.vessel being towed B.fishing vessel engaged in trawling C.vessel at anchor warning you of her location D.power-driven pilot vessel on station underway
On the approach of a warm front the barometric pressure...
单项选择题On the approach of a warm front the barometric pressure usually（）.
A.falls B.rises C.is steady D.is unreliable
On a nautical chart，the inner ring of a compass rose in...
单项选择题On a nautical chart，the inner ring of a compass rose indicates（）.
A.true directions B.compass error C.deviation D.magnetic directions
