单项选择题
A.at elongation angles near 180° B.from quadrature to opposition C.at conjunction D.at opposition
A.when the Moon is low in the sky at rising or setting B.at the new Moon phase C.when taking Moon sights during daylight D.when the terminator is nearly vertical
A.the equator to the elevated pole B.your horizon to your zenith C.your zenith to the elevated pole D.the geographical position of the Sun to the elevated pole