补全对话 A:That( )my family.That's my mother.B：（ )he?A:( )my father.B:who's(

补全对话 A:That( )my family.That's my mother.B：（ )he?A:( )my father.B:who's(
A:She's( )sister.
B:And( )they?
A:( )my grandparents.