It is very kind you to help me with my work because it is very difficult me to do it by

问题补充：

It is very kind you to help me with my work because it is very difficult me to do it by myself.

A. of； for

B. of； of

C. for；of

D. for； for

答案：

(答案→)A. of； for

B. of； of

C. for；of

D. for； for

解析：根据语境可知此题考查的是重点句型结构中介词的固定用法。It is kind of sb to do sth表示某人做某事真好；it is +形容词+for sb to do sth表示对某人来说做某事怎样，故选A。