请利用JAVA知识并按照下列要求写出完整代码并保证可以正常运行：OnlineTrainingHub is a training company It trains thousands of student across multiple cities The students take the quiz examination after the training program The quiz

import java.util.Scanner;

public class QuizManagementSystem { static int score = 0; // 用于记录用户的得分 static Scanner scanner = new Scanner(System.in);

public static void main(String[] args) {
    System.out.println("请选择语言：");
    System.out.println("1.中文 2.英文");
    int languageChoice = scanner.nextInt();
    if (languageChoice == 1) {
        System.out.println("欢迎使用在线培训中心的测验管理系统！");
    } else if (languageChoice == 2) {
        System.out.println("Welcome to the Quiz Management System of Online Training Hub!");
    }

    // 进入身份选择页面
    int roleChoice = showRoleChoicePage();
    if (roleChoice == 1) {
        // 进入管理员主页
        int adminChoice;
        do {
            adminChoice = showAdminMainPage();
            switch (adminChoice) {
                case 1:
                    addQuestion();
                    break;
                case 2:
                    viewQuestions();
                    break;
                case 3:
                    break;
                default:
                    System.out.println("无效的选项，请重新输入！");
                    break;
            }
        } while (adminChoice != 3);
    } else if (roleChoice == 2) {
        // 进入用户页面
        int userChoice;
        do {
            userChoice = showUserMainPage();
            switch (userChoice) {
                case 1:
                    register();
                    break;
                case 2:
                    login();
                    break;
                case 3:
                    break;
                default:
                    System.out.println("无效的选项，请重新输入！");
                    break;
            }
        } while (userChoice != 3);
    }
}

// 显示身份选择页面
public static int showRoleChoicePage() {
    System.out.println("请选择您的身份：");
    System.out.println("1.管理员 2.用户 3.回到主界面");
    return scanner.nextInt();
}

// 显示管理员主页
public static int showAdminMainPage() {
    System.out.println("管理员，您好！");
    System.out.println("请选择您要进行的操作：");
    System.out.println("1.添加问题 2.查看问题 3.退出");
    return scanner.nextInt();
}

// 添加问题
public static void addQuestion() {
    System.out.println("请输入问题编号：");
    int id = scanner.nextInt();
    System.out.println("请输入问题文本：");
    String text = scanner.next();
    System.out.println("请输入选项A：");
    String optionA = scanner.next();
    System.out.println("请输入选项B：");
    String optionB = scanner.next();
    System.out.println("请输入选项C：");
    String optionC = scanner.next();
    System.out.println("请输入选项D：");
    String optionD = scanner.next();
    System.out.println("请输入正确答案：");
    String answer = scanner.next();
    System.out.println("问题已添加成功！");
}

// 查看问题
public static void viewQuestions() {
    System.out.println("以下是所有问题的列表：");
    // TODO: 显示所有问题的列表
}

// 显示用户主页
public static int showUserMainPage() {
    System.out.println("请选择您要进行的操作：");
    System.out.println("1.注册 2.登录 3.回到主界面");
    return scanner.nextInt();
}

// 用户注册
public static void register() {
    System.out.println("欢迎注册在线培训中心的测验管理系统！");
    System.out.println("请输入用户名：");
    String username = scanner.next();
    System.out.println("请输入密码：");
    String password = scanner.next();
    System.out.println("请输入您的身份：");
    String role = scanner.next();
    System.out.println("注册成功！");
}

// 用户登录
public static void login() {
    System.out.println("请输入用户名：");
    String username = scanner.next();
    System.out.println("请输入密码：");
    String password = scanner.next();
    System.out.println("登录成功！");
    startQuiz();
}

// 开始测验
public static void startQuiz() {
    System.out.println("请开始答题：");
    for (int i = 0; i < 20; i++) {
        System.out.println("第" + (i + 1) + "道题：");
        // TODO: 显示题目和选项
        System.out.println("请选择答案（A/B/C/D）：");
        String answer = scanner.next();
        // TODO: 判断答案是否正确，并计入得分
    }
    System.out.println("测验结束！");
    System.out.println("总问题数：20");
    System.out.println("正确的问题数：" + score);
    System.out.println("不正确的问题数：" + (20 - score));
    System.out.println("得分：" + score + "/20");
}