菜鸟来问个有关问题！实现不了想要的结果

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    ComboBox1: TComboBox;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ListBox1Click(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses Unit2;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
     Form2.ShowModal;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   listBox1.Items.SaveToFile('chinese.txt');
   ComboBox1.Items.SaveToFile('english.txt');
 end;

procedure TForm1.Button3Click(Sender: TObject); //当按下删除时删除所选
begin
   listBox1.DeleteSelected;
   ComboBox1.DeleteSelected;
end;

procedure TForm1.FormCreate(Sender: TObject);  //从文件导入列表
begin
   listBox1.Items.LoadFromFile('chinese.txt');
   ComboBox1.Items.LoadFromFile('english.txt');
end;

procedure TForm1.ListBox1Click(Sender: TObject); //对应显示
begin
  ComboBox1.ItemIndex:=listBox1.ItemIndex;  
end;

procedure TForm1.ComboBox1Change(Sender: TObject);
begin
  listBox1.ItemIndex:=ComboBox1.ItemIndex;

end;

end.