阅读对话，回答问题。

A: Excuse me, who's that man, Xiaohua?    

B: He's my father.

A: Is that woman your mother?            

B: No, she isn't. She's my aunt, Miss Liu.

A: Where's your Mum?                  

B: Look! She's in the car.

A: Oh,I see.   

1. Where's Xiaohua's Mum?

2. Who's that man?

3. Is Miss Liu Xiaohua's Mum?

IEEE 802标准所描述的局域网参考模型对应于OSI参考模型的　　Ⅰ．逻辑链路控制层　　Ⅱ．数据链路层　　Ⅲ．网络层　　Ⅳ．物理层

A．只有Ⅱ

B．Ⅱ、Ⅲ和Ⅳ

C．Ⅱ和Ⅳ

D．Ⅰ、Ⅱ和Ⅲ