However since it has been 69 years after the last renovation no one know for sure the exact data.

但是太和殿上一次重建距此时已六十九年，没有人知道建造大殿的具体数据。

youdao

This fear mechanism is critical to the survival of all animals, but no one can say for sure whether beasts other than humans know they're afraid.

这种恐惧机制对所有动物的生存都至关重要，但没有人能肯定人类以外的动物是否知道自己在恐惧。

youdao

Sure, no one else may notice, but I know, and that’s good enough for me!

他们很低调，没有人会注意到他们的作用，但是我自己知道，这就足够了。

youdao

No one seems to know for sure.

VOA: special.2010.06.27

Of course no one can know for sure what the future holds, but we do know that bond markets, like stock markets, do change over time, and what works in one market environment may not work in future markets.

FORBES: 5 Reasons Why Bond Funds Can Help You Navigate Bond Market Headwinds Successfully

The Kommersant newspaper is already speculating that there are casualties, although no-one can know that for sure yet.

BBC: Russian media asks 'What happened?'

No one outside Apple could know that for sure, until today.

FORBES: Steve Jobs: Bad Day, Good Product