英文妻子wife的复数是wives.现在大部分地区都是一夫一妻制的!所以是不是现在这单词复数很少用了?

wives目前还是比较常用,似乎跟是不是一夫一妻制并无太大关系.
wives 作为复数是可泛指“妻子”这一身份的人,也可指若干个人的妻子们,如their wives
例句：
It has become the norm for wives to work.
妻子参加工作已经成为一种准则.
Husbands often dominate over their wives.
丈夫往往支配他们的妻子.
They came in,followed by their wives and children.
他们进来了,夫人和孩子们跟随其后.
They can be used by men as barriers against their wives .
男人可以把报纸作为阻隔妻子的屏障.