根据对话内容, 在每个空白处填入一个适当的句子, 使对话完整、合乎情境。

A：?

B：No. It is a photo of my uncle's family.

A：?

B：They are in London.

A：?

B：Yes. My cousin's name is Cui Tong.

A：?

B：Thirteen.

A：  ?

B：No. he is in Grade 8. But the girl is in Grade 7.

A：Oh. I see. She is his sister