单项选择题
A.Facade(外观)B.Composite(组合)C.Flyweight(享元)D.Adapter(适配器)
A.Facade(外观)B.Singleton(单例)C.Participant(参与者)D.Decorator(装饰)
A.AbstractB.Flyweight(享元)C.Composite(组合)D.Strategy