我对他生意上的事一概不知道。

I knew nothing of his business dealings.

《牛津词典》

阿伦小姐对他笑道：“你很会猜， 我确实不知道你怎么办到的。”——杰姆斯说：“推论。”

Miss Allan beamed at him. "You are clever to guess. I'm sure I don't know how you did it."—"Deduction," James said.

《柯林斯英汉双解大词典》

它们对美国经济有好处吗？我不知道。

Are they good for the American economy? I don't know.

youdao

So, doing those probability density dot graphs, we can get an idea of the shape of those orbitals, we know that they're spherically symmetrical.

概率密度点图上,我们可以对这些轨道的形状，有个大概了解,我们知道它们是球，对称的,我们今天不讲。

麻省理工公开课 - 化学原理课程节选

But for me, I like to look at something and just say, "I like this. I don't really know why though."

但对我来说，我喜欢看着某个东西，然后说，“我喜欢这个。但我也不知道为什么。”

关于现代美术 - SpeakingMax英语口语达人

- You open Brooks and you find yourself really apart perhaps-- I don't know how well all of you are acquainted with the texts of Freud.

也许你们看布鲁克斯的作品时会觉得很头疼-,我不知道你们对弗洛伊德那几篇文章理解的如何了。

耶鲁公开课 - 文学理论导论课程节选