题目内容：

用正确的介词和关系代词填空,
Her bother,both( )work here,ring her up every week
Her brothers,both( )work here,ring her up every week

优质解答

你是不是把题打错了,应该是brothers,（从后面的ring可以看出来,如果是brother,后面就应该是rings,单三）这样就说通了,应该填of them,意思是她住在这的两个哥哥每星期都给她打电话

追问：

Her brothers,both( )work here,ring her up every week 为什么要用of whom,具体解释一下,还有分析一下both,谢谢.