positiveness

她发言中的肯定语气让整个团队备受鼓舞。

The ___positiveness in her speech inspired the entire team.

他对实验结果的肯定驱散了所有疑虑。

His ___positiveness about the experiment's outcome dispelled all doubts.

陪审团对证据的肯定最终促成了裁决。

The jury's ___positiveness regarding the evidence ultimately shaped the verdict.