当夫妇们都能自由生5、6个孩子的时候，男女性别比例就是自然产生的。

When couples were free to have half a dozen children, there was a natural mix of boys and girls.

youdao

当夫妇们都能自由生5、6个孩子的时候，男女性别比例就是自然产生的。

When couples were free to have half a dozen children, there was a natural mix of boys and girls.

youdao