She is the only one of the persons from the mistakes.A. whom I know have learnedB. whom I

问题补充：

She is the only one of the persons from the mistakes.

A. whom I know have learned

B. whom I know has learned

C. I know who has learned

D. I know who have learned

答案：

A. whom I know have learned

B. whom I know has learned

(答案→)C. I know who has learned

D. I know who have learned

解析：考查定语从句，one of+ 复数名词，前面被the (only )修饰时谓语动词用单数形式，所以选C, I know 做插入语，who 在定语从句中做主语，句意：他是我认识中的唯一一个从错误中学习的人。