单项选择题
In the horizon system of coordinates what is equivalent to latitude on the Earth?（）.
A.Altitude B.Zenith C.Declination D.Zenith distance
单项选择题 In the horizon system of coordinates what is equivalent to the equator on the Earth?（）.
单项选择题 In order for a star to be used for a sight at lower transit，the star must（）.
单项选择题 In low latitudes，a first quarter Moon will always rise at about（）.
