import java.io.*; import java.awt.*; import javax.swing.*; import java.util.List; import java.util.ArrayList; public class Recite extends JFrame{ JLabel lblWord = new JLabel("word"); JLabel lblMeaning = new JLabel("meaning"); public void init() { setSize( 400,100 ); setLayout(new FlowLayout()); getContentPane().add(lblWord); getContentPane().add(lblMeaning); setDefaultCloseOperation(EXIT_ON_CLOSE); setVisible(true); } List<String> words = new ArrayList<>(); List<String> meanings = new ArrayList<>(); int current = 0; public void start() { new Thread(()->{ try{ readAll(); }catch(IOException ex){} new javax.swing.Timer(1000,(e)->{ lblWord.setText( words.get(current) ); lblMeaning.setText( meanings.get(current) ); current++; }).start(); }).start(); } public void readAll( ) throws IOException{ String fileName = "College_Grade4.txt"; String charset = "GB2312"; BufferedReader reader = new BufferedReader( new InputStreamReader( new FileInputStream(fileName), charset)); String line; while ((line = reader.readLine()) != null) { line = line.trim(); if( line.length() == 0 ) continue; int idx = line.indexOf("\t"); words.add( line.substring(0, idx )); meanings.add( line.substring(idx+1)); } reader.close(); } public static void main( String[] args){ Recite f = new Recite(); f.init(); f.start(); }}界面可以再好看一点；可以去掉音标；可以改变单词显示的速度；可以增加标记生词并记到生词本中；可以增加测试的功能（单词含义可以随机选4个词的含义来让用户选择）等等。附件中有两个代码，一个单词本。

好的，我会将你提供的代码添加到生词本中，并增加一个测试功能，让用户选择单词的含义。

以下是修改后的代码：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.*;

public class Recite extends JFrame {
    private JLabel lblWord = new JLabel("word");
    private JLabel lblMeaning = new JLabel("meaning");
    private JButton btnAdd = new JButton("Add to Vocabulary");
    private JButton btnTest = new JButton("Test");
    private JRadioButton[] radioButtons = new JRadioButton[4];
    private ButtonGroup radioGroup = new ButtonGroup();
    private List<String> words = new ArrayList<>();
    private List<String> meanings = new ArrayList<>();
    private List<String> vocabulary = new ArrayList<>();
    private int current = 0;
    private Random random = new Random();

    public Recite() {
        initUI();
        loadWords();
    }

    private void initUI() {
        setSize(400, 200);
        setLayout(new GridLayout(3, 2));
        getContentPane().add(lblWord);
        getContentPane().add(lblMeaning);
        getContentPane().add(btnAdd);
        getContentPane().add(btnTest);
        for (int i = 0; i < 4; i++) {
            radioButtons[i] = new JRadioButton();
            radioGroup.add(radioButtons[i]);
            getContentPane().add(radioButtons[i]);
        }
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    private void loadWords() {
        try {
            String fileName = "College_Grade4.txt";
            String charset = "GB2312";
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileName), charset));
            String line;
            while ((line = reader.readLine()) != null) {
                line = line.trim();
                if (line.length() == 0)
                    continue;
                int idx = line.indexOf("\t");
                words.add(line.substring(0, idx));
                meanings.add(line.substring(idx + 1));
            }
            reader.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    public void start() {
        new javax.swing.Timer(1000, (e) -> {
            lblWord.setText(words.get(current));
            lblMeaning.setText(meanings.get(current));
            current++;
            if (current >= words.size()) {
                current = 0;
            }
        }).start();

        btnAdd.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                vocabulary.add(words.get(current - 1));
                JOptionPane.showMessageDialog(Recite.this, "Added to vocabulary!");
            }
        });

        btnTest.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int correctIndex = random.nextInt(4);
                String[] options = new String[4];
                for (int i = 0; i < 4; i++) {
                    if (i == correctIndex) {
                        options[i] = meanings.get(current - 1);
                    } else {
                        options[i] = meanings.get(random.nextInt(meanings.size()));
                    }
                }
                for (int i = 0; i < 4; i++) {
                    radioButtons[i].setText(options[i]);
                }
                int result = JOptionPane.showOptionDialog(Recite.this, "What is the meaning of \"" + words.get(current - 1) + "\"?", "Test", JOptionPane.DEFAULT_OPTION, JOptionPane.QUESTION_MESSAGE, null, options, options[0]);
                if (result == correctIndex) {
                    JOptionPane.showMessageDialog(Recite.this, "Correct!");
                } else {
                    JOptionPane.showMessageDialog(Recite.this, "Incorrect! The correct answer is \"" + meanings.get(current - 1) + "\".");
                }
            }
        });
    }

    public static void main(String[] args) {
        Recite f = new Recite();
        f.start();
    }
}

现在，你可以运行这个代码并开始背单词了！