Everyone knows what's best for him or herself.

人人都知道对自己来说什么是最好的。

《牛津词典》

If some wish remains unfulfilled we must show our confidence in Him, for he knows best.

如果有些愿望还没有实现，我们必须对他表示信任，因为他知道得最清楚。

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He knows he's wishing for the impossible.

他知道自己在企盼不可能的事。

《柯林斯英汉双解大词典》

Two other traditions for welcoming the New Year are a midnight kiss and an attempt to sing a song that almost no one knows.

VOA: special.2009.12.28

What I'm going to do for about the next 15-20 minutes is just tell you what the class operation is like so everybody knows.

我接下来15到20分钟要做的是,要告诉你们这个班的管理是什么样的,这样大家都可知道。

麻省理工公开课 - 固态化学导论课程节选

Maybe somebody who knows Citizen Kane and would like to have a grade for the first 50 pages.

也许比较清楚了解的同学可以做,需要先读前50页的内容。

麻省理工公开课 - 电影哲学课程节选

At age three, he could be sent away from his family who knows where for who knows how long.

FORBES: Why Martin Luther King Matters

The autopilot I'd been running on for God knows how long finally shut off.

NPR: Living in the Here and Now

For who knows what information it might reveal about an individual in the light of future genomic knowledge?

ECONOMIST: A survey of the human genome