package student;public class StudentTester {    public static void main(String args[]) {     Student s1=new Student("0001","xiaohong",81,87,90);     Student s2=new Student("0002", "xiaobai", 90, 98, 89);     Student s3=new Student("0003","xiaohei", 89, 94, 98);      Student s4=new StudentXW("0004", "xiaowei", 88,99, 98, "學習委員");     Student s5=new StudentBZ("0005", "xiaoban", 97,98, 99, "班長");     System.out.println(s1.toString()+"\n"+s2.toString()+"\n"+s3.toString()+"\n"+s4.toString()+"\n"+s5.toString()+"\n");     }    }