但是一夫一妻制的家庭又有不同种类。

Within the monogamic family there are, however, many varieties.

youdao

不像其他的鱼类，它们是一夫一妻制并终生厮守。

Unlike most other fish, they are monogamous and mate for life.

youdao

一夫一妻制不仅是可能的，而且是必要的。

Monogamy is a possibility - and a necessity.

youdao

一夫一妻制不仅是可能的，而且是必要的。

Monogamy is a possibility - and a necessity.

youdao