在静止的、连续的同种流体内，等压面为( )。A．斜平面 B．曲面 C．垂直面 D．水

采用系统抽样方法，从121人中先去掉一个人，再从剩下的人中抽取一个容量为12的样本，则每人被抽取到的概率为______．

We expected there       no problem with the publication of the book by now, but it is still being printed.

A．being

B．to be

C．to have been

D．having been

第五套人民币20元纸币背面主景是长江三峡

写出泵房的岗位任务。

An analyst does research about financial leverage and gathers the following information about a company:

Units produced and sold in 2010	150000
Degree of operating leverage at 150000 units	2.5
Degree of financial leverage	2.0
Expected growth rate of unit sales in 2011	10%

The expected change in operating income for 2011 is closest to:()

A. 20%.

B. 25%.

C. 50%.