Those are model workers,some_____are young fellows.A.of whom B.of who

题目

Those are model workers,some_____are young fellows.A.of whom B.of who
我选的B,
这里的______在定语从句中作主语,怎么会是of whom呢?

答案

定语从句中,介词在关系代词之前时,如果关系代词代替的是人,则只能使用whom ,介词在句尾的话,关系代词做宾语,whom 和who 都可以,做主语只能用who