下面一段程序的功能是，单击命令按钮后将D盘temp 目录下的staff.txt 文件内容读出，并在文本框Text1中显示出来。请填空。 Private Sub Command1_ Click() Dim Line As String, FileNo As Integer Dim People As String FileNo = FreeFile Open "D:\temp\staff.txt" For Input As ______ DO While Not ______ Line Input #FileNo, Line People = People + Line + Chr(13) + Chr(10) Loop Text1.Text = People End Sub