A.15° B.30° C.45° D.60°
A.離心泵 B.螺桿泵 C.軸流泵 D.噴射泵
A.流量大、揚(yáng)程大 B.流量大、揚(yáng)程小 C.流量小、揚(yáng)程大 D.流量小、揚(yáng)程低