s=Text1．Text

  List1．Clear

  Len1=Len(s)                            ‘①

  For i=l To len1                           ‘②

    For j=1 To len1-i                       ‘③

        List1．Addltem Mid(S，j，i)         ‘④

     Next j

   Next i

运行时发现未输出所有子串，则修改（  ）

s = Text1.Text

List1.Clear

len1 = Len(s)                  ‘①

For i = 1 To len1              ‘②

For j = 1 To len1- i           ‘③

List1.AddItem Mid(s, j, i)  ‘④

Next j

Next i

运行时发现未输出所有子串，则修改（  ）

Private Sub Command1_Click()

Dim s As String, s1 As String, c As String

s = Text1.Text

For i = 1 To Len(s)

  c = Mid(s, i, 1)

  s1 =          ⑴           

  For  j =           ⑵                

   If c <> Mid(s, j, 1) Then

   s1 = s1 + Mid(s, j, 1)

   End If

  Next j

         ⑶         

Next i

Text2.Text = s

End Sub

s = "abcababcababcab": L = Len(s)

For t = 1 To L \ 2      '枚举可能的原始长度

    If L Mod t = 0 Then

        For i = t + 1 To L Step t

            If    ①   <> Mid(s， 1， t) Then Exit For

        Next i

        If i = L + 1 Then ans =   ②   : Exit For

    End If

Next t

Text1.Text = ans

上述程序段划线处①②语句依次可为（  ）