离心式锅炉给水泵是用来输送一般清水的锅炉给水专用泵，其结构形式为()。

A.单级直连式离心泵 

B.单级双吸离心泵 

C.中开式多级离心泵 

D.分段式多级离心泵

I don’t ________ to be an expert on cars, but I do know that there is something wrong with your brakes.

A．abolish

B．boycott

C．claim

D．appetite