At the end of each summer,when harvest time came,the brothers divided the grain they had grown into

题目

At the end of each summer,when harvest time came,the brothers divided the grain they had grown into two equal parts.Some of it they took to be milled into flour,from which they baked bread.请教一下这里的some of it为什么不用some of them,介词后面不是用宾格吗?

答案

这里grain 表示谷物 的总称（such as wheat、rye 、corn and rice）属于不可数名词
所以用it代替 it的宾格 还是it.