Look at the old man.He is( )

题目

Look at the old man.He is( )
1 a friend of Jane.
2 a friend of Jane's father.
3 a friend of Jane's father's.
4 a Jane's father's friend.

答案

3 a friend of Jane's father's
翻译到中文就很容易理解了,是Jane的父亲的朋友,所以都要用所有格形式