把It is clever of you to solve this problem.改成由that引导的主语从句怎么做啊?

题目

把It is clever of you to solve this problem.改成由that引导的主语从句怎么做啊?
还有这两句也是改成由that引导的主语从句：
1.It is foolish of him to go alone.
2.It is difficult for us to master a foreign language.
把第三句中的不定式后的宾语提出作主语。

答案

我觉得嘛...不改成that 引导的主语从句说得比较顺一点,就是..
You are clever to solve this problem.
He is foolish to go alone.
Master a foreign language is difficult for us.