My brother John wants to work in the factory which still .

问题补充：

My brother John wants to work in the factory which still .

答案：

解析： 通过want可知工厂还没有建成,being built正在建设,to be built要建设,选项C,最符合题意.我的兄弟约翰想去那个还在建设中的工厂工作.