我们不能只谈我们所知道的，还要考虑我们所不知道、不了解的。

Rather than just talk about what we do know, we should worry about what we do not know.

youdao

如果对提出来的问题确实不了解、不知道，可以说老实话，必要时事后提供书面的答复。

If you have no idea how to answer the question, say you don't know and, if necessary, promise to provide a written response afterwards.

youdao

此时您可能并不知道自己对哪些东西不了解。

At this point, you probably don't know what you don't know.

youdao

Specifically, what is it that American companies that, both then and now, still don't understand about China that you think you do and they don't?

美国公司对于中国的互联网行业，始终不甚了解,能否谈谈一些你知道而别人不知道的原因？

斯坦福公开课 - 百度CEO李彦宏演讲：全球最大搜索引擎的发展课程节选

I don't know if there's anything in particular that you would like to know about it, but...

我不知道你有没有特别想了解的方面，但是……

在布莱恩公园 - SpeakingMax英语口语达人

I don't know if you know the story, but Labyrinth Books is independent, it's not a chain, and independent bookstores are trying-struggling--to survive.

不知道你们是否了解,"迷宫书店"家是独立书店 而非连锁书店,对于独立书店来说,生存下去非常艰难

耶鲁公开课 - 金融市场课程节选