She certainly knows what's what.

她当然知道轻重缓急。

《牛津词典》

Why do you think she will fire you when she has learnt what's what?

为何你认为她在学会业务后会解雇你？

youdao

What's more important, some argue, is what we eat for breakfast.

一些人认为，更重要的是我们早餐吃什么。

youdao

"We looked at a very high resolution picture of the brain, where we can actually measure what's called cortical thickness.

VOA: special.2011.07.29

People who came by land you would be hearing rumblings about down the road from villages that were spread out, but if somebody comes in from the sea on a ship, you may find them there in the morning and you don't know what's what.

陆上来客总伴随着车马隆隆声,沿着途经的村庄一路传来,但是如果有人乘船从海上到来,当他早上来到时你会发现,你对他一无所知

耶鲁公开课 - 古希腊历史简介课程节选

most of it is really a kind of high-end stuff. You can see, you know, what's trendy, what's new there,

其中很多商品真是高品质的。你可以看得到，流行的、新潮的东西，

小心超额消费 - SpeakingMax英语口语达人

That's where the guys talk about what's in the news, what's on their minds.

NPR: Could The President's Week Get Any Worse?

Here's what's going to happen, here's what's going to happen, here's what's going to happen.

NPR: Really Important Football Game Coming

We've got to make that easier so that they know what's healthy and what's not.

WHITEHOUSE: Let's Move Rally in Jackson, Mississippi