用所给词的适当形式填空（七年级英语上册）
1:Is this__(you)sister?
2:This is____(he)father.
3:___(I)father is a teather.
4:___(she)sister is my friend.
5:These are____(book)
6:___you Li Ping?(be)
7:___these your friends?(be)
8:They___pens.(be)
9:I love____(they)very much.
10:____she your sister?(be)