最严重影响本案例用GNSS测点精度的是The most serious impact on the accuracy of GNSS survey points in this case is
A.
手持GNSS质量差 poor quality of handheld GNSS
B.
参考点坐标本身不准 reference points’ coordinates are not correct
C.
原图纸不准确 the original drawing is inaccurate
D.
没有找到老主楼南部的参考点 no reference points found in the south of the former main building