单项选择题
A.圆水准器轴平行于竖轴 B.管水准器轴垂直于竖轴 C.十字丝横丝垂直于竖轴 D.管水准器轴平行于视准轴
A.视准轴、管水准器轴、圆水准器轴、横轴 B.视准轴、管水准器轴、圆水准器轴、水平轴 C.视准轴、十字丝轴、圆水准器轴、竖轴 D.视准轴、管水准器轴、圆水准器轴、竖轴
A.B的高程为417.460m B.B点的高程为417.469m C.往、返测高差闭合差为+0.014m D.B点的高程为417.467m E.往、返测高差闭合差为-0.004m