抽水蓄能电站的综合效率系数，数值一般在（）之间。
A.0.5-0.65
B.0.65-0.8
C.0.7-0.9
D.0.8-0.9
参考答案：B
循少腹，贯脐入喉的经脉是
A．冲脉
B．任脉
C．督脉
D．肝经
E．肾经
He is a successful businessman; he owes his success more ________ luck than ________ ability.
