--Monitor?

--- I’m not monitor of our class. I __ with the teacher until the monitor is elected.

A．will just help

B．am just to help

C．am just helping

D．have just helped

Ⅱ型肾小管酸中毒由于（）。

A.远端肾小管重吸收碳酸氢根离子下降

B.远端肾小管分泌氢离子能力下降

C.近端肾小管重吸收碳酸氢根离子下降

D.近端肾小管分泌氢离子能力下降

E.以上都不是