polyandry

在某些部落，一妻多夫制是为了确保土地不被分割而实行的。

In certain tribes, ___polyandry is practiced to prevent the division of family lands.

在某些鸟类中，一妻多夫制很常见，雌鸟会与多只雄鸟交配。

In some bird species, ___polyandry is common where the female mates with multiple males.