单项选择题
A.DN50B.DN65C.DN80D.DN100
A.10~15m B.15~40m C.30~50m D.50~80m
A.0.20MPa B.0.30MPa C.0.35MPa D.0.50MPa
A.0.50MPa B.0.80MPa C.1.00MPa D.1.20MPa
A.20m B.30m C.50m D.80m
A.20mB.30mC.50mD.80m
A.6m3 B.12m3 C.18m3 D.30m3