} void show(){ System..out.println("所在学校："+name): System.out.println("学号："+sNum): System..out.println(性别："+sex): System..out.println("生日："+birth): System..out.println("姓名："+sname); System.out.println("成绩："+Score): } } class Undergraduate extends Student{ String department: String major: void setDeparment(String c){ department=c; } void setMajor(String d){ major=d; } void showl(){ super.show(); System.out.println(“系部："+department): System.out.println("专业："+major)): class Student{ public static void main(String arg[]){ Student A=new Student(); Undergraduate B=new Undergraduate(); B.setName("许翼")： B.setScore(95); B.setDeparment("信息工程系")： B.setMajor("计算机网络")： B.showl(); 2.从键盘或者命令行输入3个数，求这三个数的最大值。 import javax.swing.JOptionPane; public class MaxNum public static String sum(int a,int b,int c,int d){ if(a>b){ d=a; if(b>d){} void show(){ System.out.println("所在学校："+name); System.out.println("学号："+sNum); System.out.println("性别："+sex); System.out.println("生日："+birth); System.out.println("姓名："+sname); System.out.println("成绩："+Score); } } class Undergraduate extends Student{ String department; String major; void setDeparment(String c){ department=c; } void setMajor(String d){ major=d; } void show1(){ super.show(); System.out.println("系部："+department); System.out.println("专业："+major); } } class Student{ public static void main(String arg[]){ Student A=new Student(); Undergraduate B=new Undergraduate(); B.setName("许翼"); B.setScore(95); B.setDeparment("信息工程系"); B.setMajor("计算机网络"); B.show1(); } } 2.从键盘或者命令行输入 3 个数，求这三个数的最大值。 import javax.swing.JOptionPane; public class MaxNum { public static String sum(int a,int b,int c,int d){ if(a>b){ d=a; } if(b>d){