Tai Gong replied: There are eight forms of tests by which you may know it. First, question them and observe the details of their reply.

太公说：有八种考验方法：一是提出问题，看他知道得是否详尽清楚；

youdao

A lot of Americans may be surprised to know that it was written without saying anything directly about sports.

VOA: special.2010.03.04

Unfortunately, this thought, popular as it may be, that it takes one to know one, just seems false.

不幸的是,这样的想法,即同类者互知,可能很流行,但实际上是错误的

耶鲁公开课 - 死亡课程节选

And since we don't know the absolute up and down in the universe, it is possible that some of the electrons may be spinning up.

由于我们在宇宙里,并不知道什么是绝对的上和下，所以说上面的现象很有可能是,一些电子向上自旋引起的。

麻省理工公开课 - 固态化学导论课程节选

Younger drivers may know it as Calle Ocho.

CNN: Why your trusty GPS sometimes fails you

"Hey, that Japan Air may know it but they have fuel spewing out the leftward wing quite a bit, " the pilot of another plane told the control tower, which radioed the JAL crew and halted takeoff.

CNN: Airline: Dreamliner fuel leak due to an open valve

Because a lot of times people give advice and it's misguided or it's self-seeking and they may not know it.

NPR: Help 'Ask Amy' Write A Commencement Speech