My mother used to what she did every day.A. writing downB. write downC. wrote downD. be w

My mother used to what she did every day.
A. writing down
B. write down
C. wrote down
D. be written down

A. writing down(答案→)B. write downC. wrote downD. be written down解析：句意:我妈妈过去常常把她每天做的事情写下来。used to 的意思是过去常常做某事，后面应该跟动词的原形，故选B。be used to 后跟动词的ing形式，表示习惯于某事。

这个解释是对的