It has never existed. It will never exist.

它从来没有存在过，将来也永远不会。

youdao

I know, I know... I'm an idealist, and such a world will never exist.

我知道，我知道···我是一个理想主义者，这样完美的世界或许永远不可能存在。

youdao

They can also never exist in unknown or undesirable state because of an exception.

它们也不可能因为异常的发生而处于一种未知的或是无法预期的状态中。

youdao

And many have imagined," one thinks here of Plato, perhaps, but also to Christianity" Many have imagined republics and principalities that have never been seen " or known to exist in truth.

因为已有太多的梦想家“,其中一人即柏拉图，但也可能是基督教“,“已有太多对共和,与君权的幻想,而那从来都未真实地存在。

耶鲁公开课 - 政治哲学导论课程节选

Still, environmentally sound natural gas production will never exist until producers themselves get serious about environmental management.

WSJ: Is Natural Gas the Road to a Clean Energy Future?

So, the Federal government is requiring our company to buy a product that does not exist, and likely will never exist.

FORBES: Regime Uncertainty and Obamacare

Zynga grew fast and hard under circumstances that will never exist again, and now its seeing whether or not it can hang onto that growth.

FORBES: Zynga Stock Sinking Along With Facebook -- Is Now The Time to Buy?