用DJ2和DJ6觀測一測回的中誤差分別為()
A.±2″、±6″ B.±2″、±6″ C.±4″、±12″ D.±8″、±24″
A.n B.1/n C. D.1/
A.±10.8mm,1/12200 B.±9.4mm,1/14100 C.±4.7mm,1/28200 D.±5.4mm,1/24500