A.網(wǎng)格北=磁北+磁偏角-收斂角B.網(wǎng)格北=磁北+磁偏角+收斂角C.網(wǎng)格北=磁北-磁偏角-收斂角D.網(wǎng)格北=磁北-磁偏角+收斂角
A.大、小表指針都指0B.小表針指0,大表指針指9C.小表針指9,大表指針指0
A.10針腳—7針孔B.10針孔—7針孔C.10針腳—7針腳