A.赤道B.黃道C.銀道D.地平圈
A.太陽赤經(jīng)每日增加約4mB.太陽赤經(jīng)每日減小約4mC.恒星赤經(jīng)每日增加約4mD.恒星赤經(jīng)每日減小約4m
A.±21sB.±29sC.±8sD.±50s