单项选择题
Because the actual center of some planets may differ from the observed center，the navigator applies a correction known as the（）.
A.phase correction B.refraction correction C.semidiameter correction D.augmentation correction
单项选择题 As observed from the Earth，the angle between lines from the Earth to the Sun and the Earth to an inferior planet is known as（）.
单项选择题 Apparent altitude is sextant altitude corrected for（）.
单项选择题 An amplitude of the Sun in high latitudes（）.
