选用方框中所给的句子补全下列对话。 Pat : Good morning, Lily. Lily: (1) Pat: (2) Lily: I'm twelve. Pat : I'm twelve, too. (3) Lily: She's my cousin, Lucy. (4) Lucy: Hi Lily. Are we classmates? Lily: (5) A. How old are you? B. She is polite and helpful. C. Yes, we are. D. Good morning, Pat. E. Who is she?