单项选择题
Concerning a celestial observation，the azimuth angle is measured from the principal vertical circle to the（）.
A.Greenwich celestial meridian B.hour circle of the body C.local celestial meridian D.vertical circle of the body
单项选择题 Compliance with the terms of the load line certificate on a ship is the responsibility of the（）.
单项选择题 Complete information on weather broadcasts throughout the world is contained in（）.
单项选择题 Compared to internal structural plating，the exterior hull plating on a ship is usually（）.
