费解的抽象类!
When we define a class , we can leave a method blank. This kind of class is abstract. An abstract class is one that is not used to construct objects, but only as a basis for making subclasses. The class and it’s blank method are abstract by adding the modifier "abstract" to their definitions. For an abstract method, the block of code that gives the implementation of an ordinary method is replaced by a semicolon. An abstract class exists only to express the common properties of all its subclasses. An implementation must be provided for the abstract method in any concrete subclass of the abstract class.
谁能帮我翻译翻译,我的英语菜!非常感谢!