求助：独立主格的用法

In good years, the patchwork of green fields that surround the San Joaquin
                        Valley town bustles with farm workers, many of them in the area just for the season.

(A) surround the San Joaquin
                    Valley town bustles with farm workers, many of them

(B) surrounds the San Joaquin
                    Valley town bustles with farm workers, many of whom are

(C) surround the San Joaquin
                    Valley town bustles with farm workers, many of who are

(D) surround the San Joaquin
                    Valley town bustle with farm workers, many of which

(E) surrounds the San Joaquin
                    Valley town bustles with farm workers, many are

答案A

为什么这里用代词them，而有的情况下用many of which，他们在用法上的区别是什么呢？

many of them用于引导独立主格,而 which用于引导定语从句。

至于many of which,我觉得既然用了which那就应该是非限制型定语从句，也就是说定语从句所描述的特性which所指代的事物都应该具备，那么many of which是不是逻辑有问题呢？反正我没有见到过many of which是正确答案的题目。如果LZ见到，请告知。

三、独立主格结构的功能

独立主格结构主要用于描绘性文字中，其作用相当于一个状语从句，常用来表示时间、原因、条件、行为方式或伴随情况等。

具体请看：