of which和of whom在定语从句中的哪种情况下才出现?

当替代先行词的部分,即which或whom,在定语从句中做含有of 的动词结构或介词结构的宾语的情况下才出现.以of which 的使用为例,例释如下：
1.The house _______ windows face south is our reading-room .
A .of which B .whose C .which D .its
此题正确答案是B
2.The house _______ the windows face south is our reading-room.
A .of which B .whose C .which D .its
此题正确答案是A.
3.The house whose roof was damaged now has been repaired .
=The house of which the roof was damaged has now has been repaired .
4.of which 除了可以表示所属关系外,还可以用来表示整体的关系：
In Barcelona the Chinese team got 16 gold medals ,of which 12 were won by women .
There are 102 elements found in nature,of which most are metals .
The stories about the Long march,of which this is one example ,are well written .