translation.en: Attached to the facial bones that define our face's structure are the muscles that deliver our facial expression, our universal language of expression, our social-signaling system.
translation.zh: 依附于面颅骨 用来勾画我们面部结构的 是传递我们面部表情的肌肉, 我们通用的表情语言 我们的社会信号体系。