"Unlikely but not impossible," he says.

他说：“不太可能，但并非完全不可能。”

youdao

Wind resistance makes this impossible event even more unlikely.

风的阻力让这件不可能的事情变得更不可能。

youdao

That seems unlikely (although not impossible).

这似乎是不可能的（尽管并非不可能）。

youdao

It's not impossible but it's pretty unlikely.

不是完全不可能,只是可能性很低

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Unison said it was "unlikely if not impossible for Circle to pay it back".

BBC: Union urges review of Hinchingbrooke's Circle contract

In most of Africa (Mauritius is a member of the African Union), the return of a white leader to power would be unlikely if not impossible.

ECONOMIST: Mauritius changes government

Every manager knows in his heart of hearts that it is highly unlikely or indeed impossible that the client will receive the performance he or she is led to believe is possible.

FORBES: Everyone Wants Kool Aid: Pruning the Money Management Tree (October 29, 2008)