We have no firm evidence to support the case.

我们没有确凿的证据支持这个论点。

《牛津词典》

This man may have killed others but unfortunately we have no firm evidence.

这名男子可能还杀过别的人，只可惜我们没有确凿的证据。

《柯林斯英汉双解大词典》

‘You’d think it was based on firm evidence of health benefit. Think again!

如果你认为有充足的证据来证实此建议有益身体健康，那么你就又错了！

youdao

Why waste a cut in interest rates until you see some firm evidence that it is really necessary?

BBC: Sniffing out an ECB rate cut

Mr Marriott is still looking for firm evidence of his ancestor's role in bringing the bird to England.

BBC: William Strickland: The man who gave us the turkey dinner

Authorities have stressed that all the latest moves were precautionary and there was no firm evidence the disease has reached the republic.

CNN: Seven new UK foot-and-mouth cases