A.轉速 B.水力螺距 C.摩阻常數(shù) D.測速歷時
A.0.2h.0.6h.0.8h B.0.2h.0.4h.0.8h C.0.4h.0.6h.0.8h D.0.2h.0.4h.0.6h
A.越短越好 B.越長越好 C.大約100s D.不受限制