You not know it.

你不知道它。

youdao

If you must move, don't follow a stream unless you know it, and in that case, you are not lost.

如果你非要走动的话，别顺着溪流走，除非你对它很熟悉。但是如果你很熟悉，那你就不会迷路了。

youdao

It must be worrying for you not to know where he is.

你不知道他的下落一定很着急。

《牛津词典》

Montclin did not move. "You know as well as I do that it is no use to tell Athnaise anything,"

VOA: special.2009.06.27

Usually when you know why it's not working, it's obvious what you have to do to make it work.

通常你明白了出错的原因后，很明显你必须让程序正常运行起来。

麻省理工公开课 - 计算机科学及编程导论课程节选

So it really, you know, becoming familiar with the different methods is best done through experience, not through books.

所以，真的，你知道，熟练掌握不同的方法最好是通过经验，而不是通过书。

迷上网页设计 - SpeakingMax英语口语达人

They have to do what they have to do to get it, and so you've just given in essence, though you may not know it, carte blanche for a lot of problems to occur.

NPR: Ex-Powell Staffer Discusses Cheney Role in Iraq War

You may not know it from the weather, but for retailers spring isn't far off.

FORBES: Magazine Article

You might not know it but Design Week, New York, begins this Friday.

FORBES: After Tech Boost, Design Begins to Pique Interest in New York