Many factors influence a student in his/her study, I think are out of a teacher’s control.
A. most of them
B. most of which
C. most of what
D. most of that
网友回答
A. most of them
(答案→)B. most of which
C. most of what
D. most of that
解析：这个句子尤其要注意区分A和B选项的不同，只要我们注意了标点符号就知道这并不是个并列句，所以不能选A。因为是逗号，说明后面是个非限制性定语从句，这里考查的是介词＋which的用法，原句可还原成…most of the factors …。