nicehost-
回答如下：
take sth for granted / take it for granted that ...是一个动词短语，意思是“认为……是想当然的(理所当然的)，认为……是真的(没有问题的)”，其中介词短语for granted 是宾补，it是形式宾语，that从句是真正的(逻辑)宾语。例如：
Some of us often take the on-line fake news for granted. 我们中的一些人常常对网上的假新闻信以为真。
We take it for granted that he is successful. 我们认为他的成功是理所当然的。
一般来说，英语介词后面通常跟名词、代词、数词、动名词、名词从句(if / that 从句除外。 但介词except后面可以跟that从句。)作宾语。但是，有些介词也有后跟形容词、副词、介词短语、不定式、过去分词(非常少见，主要见于有些固定搭配或特殊结构。)的。前者是一种惯例，后者是特殊情况。毕竟先有语言，后有语法，语法无法包揽语言的万象，对后者须作为特殊情况来记忆。特殊情况的范例：
1. He will come for sure / certain.
2. Tibet is very far from here.
3. He lives near here.
4. They come from around the world.
5. He has no choice but / except to leave.
6. She did nothing but / except cry.
7. I can"t stay for long.
8. He came out from behind the door.
9. It is too hot in here.
10. We looked everywhere except here.
11. The temple is beautiful except that it is a little small.
12. I can"t regard the matter as settled.
13. They finished the task as requested.
14. They took my kindness for granted.
本句结构分析：
定语That + 主语self-efficiency + 复合谓语cannot be taken +宾补for granted(granted作介词宾语) + 条件状语从句。
康康map-
be taken for granted 被认为是理所当然
take it for granted 理所当然
这是一个比较特殊的情况，因为for granted是一个固定短语，for后面跟的是一个过去分词
例如：I take it for granted that a mother should love her child.
我认为母亲爱孩子是理所当然的．
因此，可以把它看作是一个特殊的句型结构。
牛云-
某些时间副词和地点副词可作某些介词的补足成分。有时形容词也可作介词补足成分。
但这里taken for granted是习语：认为（某事）当然。主语：That self-sufficiency ；谓语动词：cannot be taken for granted；条件状语： if yields continue to slow down or reverse.
gitcloud-
take …for granted 是固定短语，认为…是理所当然的。
for granted是介词短语做宾语补足语
wpBeta-
take for granted 是固定搭配的短语，意为“理所当然的”。背下来就好。