A.50m.50m B.50m,75m C.100m,50m D.100m,75m
A.0.30 B.0.45 C.0.60 D.0.75
A.直埋敷設(shè) B.隧道敷設(shè) C.水下敷設(shè) D.排管敷設(shè)