.,perhaps with people you know well

问题描述:

.,perhaps with people you know well
这句话中you know well此定语从句的先行词老师说是who,错了吧.正确的是啥?
如果是who,关系副词还可以省略?

先行词是people,关系代词(引导词)是who,作宾语试可以省略.