class Student {  protected String name;  protected int age;  public Student(String name,int age){   this.name=name;   this.age=age;  }  public void show(){   System.out.println("学生的名字为："+this.name+"，学生的年龄为："+this.age);  } } class Undergrdute extends Student {  private String degree;  public Undergrdute(String name,int age,String degree){   super(name,age);   this.degree=degree;  }  public void show(){   System.out.println("学生的名字为："+super.name+   "，学生的年龄为："+super.age+   "，学生的专业为："+this.degree);  } } public class Test{  public static void main(String[] args){   Student s1 = new Student("小明",20);   Student s2 = new Undergrdute("小辉",25,"计算机");   s1.show();   s2.show();  } }