补全对话。

A: Good morning, Sally!

B: Good __1__ , __2__ are you today?

A: I'm __3__, thank you .

B: __4__ that ?

A: Oh, It's a __5__ of my family.

B: Let me have a look. __6__ is she? Is she your mum?

A: No, she isn't. She is my __7__. We call (称呼) her Aunt Huang. And this is my mother.

B: __8__ is your mum?

A: My mum is a doctor.

B: Who __9__ this boy? Is your brother?

A: No, he is my __10__. We call him Cousin Tony.

已知某子系统为外界提供功能服务，但该子系统中存在很多粒度十分小的类，不便被外界系统直接使用，采用 (57) 设计模式可以定义一个高层接口，这个接口使得这一子系统更加容易使用；当不能采用生成子类的方法进行扩充时，可采用 (58) 设计模式动态地给一个对象添加一些额外的职责。

A．Facade(外观)
B．Singleton(单例)
C．Participant(参与者)
D．Decorator(装饰)