Question

请帮忙分析一下这句话的句子成分。

句子：Clay, moreover, is cheap, and forming it into tablets is easy, factors that helped the clay tablet become the preferred writing material not only throughout Mesopotamia but far outside it as well, in Syria, Asia Minor, Persia, and even for a while in Crete and Greece.
疑惑：我觉得主句是 Clay is cheap and forming it into tablets is easy. 但是这样的话， factors 后面好像都是从句，光一个 factor 不知道是用来干什么？

Answer 1

factors引导的是同位语从句，修饰前面那句话。