A.基准线法 B.投影响 C.监视性变形观测
A.1/10451 B.-1/10451 C.1/10450
A.20 B.15 C.10 D.5
A.1 B.2 C.1.5 D.5
A.+0.1 B.-0.1 C.±0.1 D.±0.2