1、in the end应该不能带of的吧.in the end=at last=finally,意为“最 后,最终”.是一个句子成分,修饰整个句子如:in the end,it was more than he could bear(最后,他再也忍不住了)
2、at the end (of...可省略)在(...的)未端:在(...后期)
3、who 是做主语成分 后面接动词
如 who did it?
whom 是做宾语成分 动作的对象
如 whom did you give the pen to
如果改成祈使句就很明白
you gave the pen to whom( 宾语)