离心泵的转速可用（）的方法改变。
A.改变流量
B.改变扬程
C.采用变频调速器
D.改变允许吸入高度
参考答案：C
如何对收治ICU的病人进行病情评估。
The plan was when it was discovered how much the scheme would cost. [ ]
A.released
B.deserted
C.resigned
D.abandoned
