关于There is difficulty to do/in doing sth的用法

问题描述

Though there were great difficulties _______, he never gave up.
A. in overcoming   B. to overcome
答案是选不定式(B)，但为什么不能选 in doing sth (A)呢？英语不是有一个句式是 there is some difficulty (in) doing sth 吗？

老师答疑

曾老师：

这里的 to overcome 是反射不定式作定语修饰 difficulties，difficulties 是 overcome 的逻辑宾语。全句意为：尽管有巨大的困难要克服，但他从未放弃。而在 thereis difficulty (in) doing sth.“作某事有困难”这个结构中，(in) doing sth.是状语而不是定语。

胡老师：

谢谢曾老师！