改变泵的扬程的方法是变（）、（），也可以（）。
参考答案：离心泵的转速；叶轮外径；改变泵的扬程
Being not far the sea, London is famous its fog.
A．from; with
B．from; for
C．away; with
D．away; for
26. －Do you know what Miss Black does for a living?
－I have no idea at all, I think she could be _______ but a singer.
A．anything
B．anybody
C．nothing
D．Everybody
