My mother all the cleaning for my family but recently she has been too busy teaching to

问题补充：

My mother all the cleaning for my family, but recently she has been too busy teaching to do it.

A. will do

B. is doing

C. does

D. had done

答案：

A. will do

B. is doing

(答案→)C. does

D. had done

解析：句意：我的母亲包揽家里的清洁工作，但是最近她忙于教学而无法做清洁工作。根据句意可知母亲做清洁工作是经常性的动作，所以用一般现在时。故选C。