有一种理论认为，两足动物的进化与核心家庭有关：一夫一妻制的父母合作照顾他们的后代。

One theory is that bipedality evolved in conjunction with the nuclear family: monogamous parents cooperating to care for their offspring.

youdao

一夫一妻制一般是指即将要结婚的两个人六个月的相处时间，经过了一年的约会后，订婚是比较现实的下一个步骤。

Monogamy usually comes within six months for those who will marry, and after a year of exclusive dating, engagement is a realistic next step.

youdao

两年前，在嫁给萨科齐之前不久，布吕尼曾声称“厌烦一夫一妻制”，这在当时广为流传。

Mrs Bruni-Sarkozy famously declared that "monogamy bores me" just before marrying Mr Sarkozy two years ago.

youdao