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

Yet no one can say they were not warned.

然而没有人能说他们没有得到预警。

youdao

No one can say how these two trends will play out.

没有人可以说明这两种模式会如何上演。

youdao

So,the scientists say no one can really predict the future of the ocean.

VOA: standard.2010.06.08

They could get together and say we are writing a new rule on how these gold proceeds can be used, but no one has taken the initiative to start to make that happen."

VOA: standard.2009.04.20

But no one can say which way she went or whether she got into a car.

CNN: Cold case: No signs of missing teen in recent search

Nearly a year into the crisis, no one can say whether Asia has hit bottom.

CNN: FROM BAD TO WORSE

No one can say for certain just how she survived the water and the wreckage around her.

WHITEHOUSE: Standing with Japan