题目内容
在下面定语从句中填入适当的介词
She has three children, all ________ whom are at school．
He built a telescope ________ which he could study the skies．
The woman, ________ whom I learned the news, is a nurse．
The wolf ________ which the sheep was killed was shot．
There is a tall tree outside, ________ which stands our teacher．
