英语问题Withoutfacts,wecannotformworthwhileopinionforweneedtohavefactualknowledgeuponwhichtobaseourthinking.uponwhichtobaseourthinking.是个定语从句,怎么连谓语动词都没有,是不是省略了什么?

Question

英语问题
Without facts,we can not form worthwhile opinion for we need to have factual knowledge upon which to base our thinking.
upon which to base our thinking.是个定语从句,怎么连谓语动词都没有,是不是省略了什么?

Answer 1

从形式上看 upon which to base our thinking 的结构是“介词+关系代词+不定式短语”.
一、不定式短语也可以作相当于定语从句的后置定语,这种定语分下列几种情况：
1.单纯不定式作定语,结构为：
被修饰词 + 不定式；如：
The man to leave for US next week is my friend.下周到美国的那个人是我的朋友.
That's the way to do it.那样做才对.
2.不定式复合结构作定语,结构为：
被修饰词 + for sb.+ 不定式；如：
There is a lot of work for us to do.有很多工作要我们去做.
3.带有疑问词的不定式作定语,结构为：
被修饰词 + 疑问词 + 不定式；如：
We want to know the right date when to start.我想知道确切的出发日期.
4.带有介词家关系代词which的不定式作定语,结构为：
被修饰词 + 介词 + 关系代 + 不定式；如：
We want to know the right date on which to start.我想知道确切的出发日期.
注：3 和 4 中的例句其实是一样的,只不过是把 3 中的 when 换成了 4 中的 on which
二、不定式作后置定语表示未来的行为,多数可以改写为定语从句,但需要加入表示将来的助动词 will,be going to,be to 或情态动词 can,should,must,have to 等.
The man to leave for US next week is my friend.改写为
——The man who will leave for US next week is my friend.
There is a lot of work for us to do.改写为
——There is a lot of work which we must do.
We want to know the right date when to start.改写为
——We want to know the right date when we/they should start.
三、由上可知 upon which to base our thinking 不是定语从句,而是相当于定语从句的不定式短语作后置定语,因此这句话也可以改写为：
...for we need to have factual knowledge upon which we can base our thinking.（也可以根据山下文语气选用 will base,are to base,are goingto base 等）