【帮忙分析一下下面这个句子的语法Participantsinthisenterpriseweresuppliedwithbicycles,whichtheyusedtodeliverparcelsandmessages,andwichtheywererequiredtopayforgraduallyfromtheirwages.这里的which应该就是定】

　　帮忙分析一下下面这个句子的语法

　　Participantsinthisenterpriseweresuppliedwithbicycles,whichtheyusedtodeliverparcelsandmessages,andwichtheywererequiredtopayforgraduallyfromtheirwages.这里的which应该就是定语从句的先行词了,但是在从句中做什么成分呢?宾语的话也有点别扭啊?