已知一台水泵的叶轮直径为400mm时,轴功率是80KW,求当叶轮直径切割20mm后的轴功率是多少?
参考答案:
It’s my ___________ time to go to Beijing. I never went there before.
A.two
B.second
C.one
D.first
肺痨之阴阳虚损证最佳方为()
A.保真汤
B.月华丸
C.八珍汤
D.补天大造丸
E.补肺汤