1． 该类支持哪些接口；2． 完成任务需要哪些对象；3． 如何使用该类的对象；4． 是否可以直接实例化类；5． 接口有哪些方法和属性；6． 是否有其它类也支持该接口；7． 对象间的关系-1. What kind of interface　2. What are the targets of the completion of tasks　3. How to use this kind of object　4. Whether the category can be directly instantiated　5. What are the interface methods and properties　6. Are there other types of support to the interface　7. The relationship between objects