Dim a(l To 100) As String

Private Sub Commandl_Click()

  Dim c As Integer, t As String, ans As String

  s = Textl. Text

  k = Val(Text2. Text)

  ans =“”

  For i = 1 To Len(s) - k - 1

    c = c + 1

    a(c) = Mid(s, i, 1) + Mid(s, i + k + 1, 1)

    If check(c) Then

      ans = ans + a(c) + "，"

    Else

      c = c - 1

    End If

  Next i

  Text3. Text = ans

End Sub

Function check(k As Integer) As Boolean

  Dim i As Integer

  check = True

  For i = 1 To k - 1

    If a(i) = a(k) Then check = False: Exit For

  Next i

End Function

若该程序段执行后，在文本框Text1中输入的字符串长度不超过10，文本框Text2中输入的值在0到8范围内（输入输出都不包括双引号本身），下列说法不正确的是（  ）