| 1. | Derived items that are maintained in a list by the
派生类在列表中维护的就是这些 |
| 2. | Derived classes supporting specific protocols , such as
支持特定协议的派生类（如 |
| 3. | When overridden in a derived class , paints a
在派生类中被重写时，将绘制具有指定 |
| 4. | And add new properties to the derived class
派生类并向派生类添加新属性时都重写 |
| 5. | A derived class can invalidate the cached version by calling
派生类可以通过调用 |
| 6. | When overridden in a derived class , retrieves the
当在派生类中重写时，检索事件的 |
| 7. | Method to dispose of the derived class s resources
方法以释放该派生类的资源。 |
| 8. | How to : access a variable hidden by a derived class
如何：访问被派生类隐藏的变量 |
| 9. | When overridden in a derived class , gets an
当在派生类中被重写时，获取表示当前 |
| 10. | This method must be implemented by the derived class
该方法必须由派生类来实现。 |
