But testing these theories is hard, so nobody knows if they are true.

然而，验证这些理论相当困难，因此这些理论正确与否无人知晓。

youdao

It has been celebrated for so long, but nobody exactly knows how it started.

人们已经庆祝它很久了，但没有人确切地知道它是如何开始的。

youdao

You know, dears, in the old countries there are many fine stories about things which happened so very long ago that nobody knows exactly how much of them is true.

朋友们，你们都知道，在那些古老的王国里总流传着很多传奇故事。 这些故事流传了很久很久 以至于没有人知道这些故事当中哪些真的发生过。

youdao

"I don't think at this stage, nobody knows whether BP will be forced to be broken up, whether it might actually end up being so weakened that it falls into the arms of somebody else."

VOA: standard.2010.06.18

It has to stay relevant to the market, so nobody really knows where these interest rates come from because no one person sets them.

交易价格必须与市场价格一致,因此没有人能确定,利率的决定过程,因为个人无法决定利率

耶鲁公开课 - 金融市场课程节选

Nobody knows who it is,so they call it,they find it wandering on the streets.

没人知道他是谁，他流落街头。

耶鲁公开课 - 死亡课程节选

According to immigration officials, Mr. Cabrera had already visited Caracas on February 23, 2007 but his passport was not stamped when he returned to the country, so nobody knows the exact amount of days he spent in Venezuela.

CENTERFORSECURITYPOLICY: Chavez's dangerous intervention in Peru

Another rule: Nobody knows everything, so nobody can win alone.

FORBES: An Organizational Ghost Story

When that programme was launched eight years ago, it promised to halve the number of malaria deaths by 2010 but malaria data are so vague that nobody knows the baseline (see article).

ECONOMIST: America and malaria