题目内容：

不定式和分词的区别
fearing no difficulty and refusing (to be frustrated), they went on persistently with their plan.
为森马不可以用直接用frustrated,过去分词不是也有被动的意思在里面吗?为什么要用不定式的被动啊?

优质解答

refuse to do sth是固定搭配,所以不能直接用 frustrated