定语从句的主语support and assistance 和family(家人） 是什么关系呀?
家人【的】支助是不是?
the support and assistance 【of 】the family
whose 等于【of】 the family
明白?without 是介词啊？是的without whose support and assistance， 整个是个介词短语， 在此相当于虚拟条件句“If it hadn't been for their support and assistance"要是没有他们的支助”