戒指和书，我看到了我想要的幸福

摘要： 练习12 package cn.ch.w; public abstract class Person { private String name; private int age; public String getName() { return name; } public void setNam 阅读全文

摘要： public class Circle { private double radius; public Circle(){ this.radius=1; } public Circle(double radius){ this.radius=radius; } public double get... 阅读全文