So difficult it to work out the problem that I decided to ask Tom for advice. A. I did f

问题补充：

So difficult it to work out the problem that I decided to ask Tom for advice.

A. I did find

B. did I find

C. I have found

D. have I found

答案：

A. I did find

(答案→)B. did I find

C. I have found

D. have I found

解析：句子使用的基本句式为so…that…结构。按英语语法，当该结构的so…置于句首时，其后的句子(主句)要用倒装语序，如：So loudly did he speak that even people in the next room could hear him. 他讲话声音那么大，隔壁屋里的人都听得见。