--Monitor?- I’m not monitor of our class. I with the teacher until the monitor is elec

问题补充：

--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

答案：

A. will just help

B. am just to help

(答案→)C. am just helping

D. have just helped

解析：考查时态，句意是：--班长？--我不是班长，我只是帮老师忙直到班长选出来。说明帮忙是暂时的，现在进行时可以表示现阶段暂时的动作，选C。