请问这句话中的whom是前句中的people with吗?这是定语从句?是的话whom不是该做从句中的宾语吗?

题目

请问这句话中的whom是前句中的people with吗?这是定语从句?是的话whom不是该做从句中的宾语吗?
The health-care law has been celebrated by people with serious illnesses,some of whom have been unable until now to obtain coverage.

答案

whom就是前句中的people with serious illnesses
some of whom have been unable 这个定语从句中,some of whom=some of the people with serious illnesse,
因此=some of the people with serious illnesse have been unable to obtain The health-care law's coverage
因此是做主语,因为有of 介词提前,不能用who,只能使用whom
医保法受到了身患严重疾病患者的欢迎,因为,他们中很多人以前享受不到这些医疗保险福利