most of them与most of whom与most of which的用法区别

them 是they 的宾格,指代的是人,most of them 可做主语和宾语.
Most of them are probably unaware that corporations are
going out of business faster and faster
whom 是 who的宾格,一般在定语从句中指示宾语,或者在疑问句中指示宾语.
They say that's the best method to assess their students,most of
whom are working adults
which 用作关系代词的时候一般都是指示物,可以做宾语也可作主语.一般都是定语从句,或者非限定性定语从句.
There are regular bus routes around our town most of which
pass the college