“这太荒谬了，” 他悄声说道。

"This is ridiculous," he whispered ___under ___your ___breath.

她一直在抱怨天气热，但只是低声嘀咕。

She kept complaining about the heat, but only ___under ___your ___breath.

在那场无聊的讲座中，我能听到邻座在轻声叹气。

During the boring lecture, I could hear my neighbor sighing ___under ___your ___breath.