以“介词+疑问句”（如 whom / which / what / whose / where / when 等）开头的特殊疑问句是一种比较正式的表达，在非正式文体中，如此的介词一般可以放到句末去。如：
正式：In which century did he live? 他生活在什么世纪?
非正式：Which century did he live in? 他生活在什么世纪?
但，对于 to what degree开头的特殊疑问句怎么样将介词 to 移到句末呢？譬如下面两句：
To what degree is he wealthy? 他富裕到什么程度？
To what degree are you interested in Japanese? 你对日语的兴趣达到了什么程度?
▲你说得没错，以“介词+疑问句”（如 whom /which / what / whose / where / when 等）开头的特殊疑问句是一种比较正式的表达，在非正式文体中，如此的介词一般可以放到句末去。又如：
正式：To whom were you talking? 你刚刚在跟哪个谈话？
非正式：Who were you talking to? 你刚刚在跟哪个谈话？
正式：In which drawer does he keep it? 他把它存放在哪一个抽屉里？
非正式：Which drawer does he keep it in?他把它存放在哪一个抽屉里？
▲但，to what degree 是一个固定搭配，不适合拆开用，下面两句句首的介词 to 不适合放到句末：
To what degree is he wealthy? 他富裕到什么程度？
To what degree are you interested in Japanese? 你对日语的兴趣达到了什么程度?
▲《柯林斯高阶英汉双解学习词典》在 degree 词条有如此一条使用方法：
You use expressions such as to what degree and to the degree that when you are discussing how true a statement is, or in what ways it is true.
To what degree would you say you had control over things that wenton? 你觉得发生的事情在多大程度上是在你的掌控之下？
