Private Sub Command1_Click()

 Dim n As Integer, s As Integer

 n = 10

 s = 10 ︿ n

 Text1.Text = Str(s)

End Sub

运行程序时，单击命令按钮Command1后弹出如图所示的出错信息提示，引起该错误的原因是（   ）

例如：当明文M=HelloWorld，密钥K=abc时，密文C=HfnlpYosnd。运算过程如下所示：

明文：HelloWorld

密钥：abcabcabca

密文：HfnlpYosnd

依据上述算法描述设计了如下VB程序。请回答下列问题：

Private Sub Command1_Click()

Dim i As Integer, j As Integer, sum As Integer

Dim n As Integer, k As Integer, tmp As String

n = Val (Text1.Text)

sum = 0:List1.Clear

For i = 1 To n-1

 j=i

 Do While sum < n

  {#blank#}1{#/blank#}

 j = j + 1

 Loop

 If sum = n Then

  {#blank#}2{#/blank#}

  For k=i+1 To j-1

   tmp = tmp + “+” + Str(k)

  Next k

  List1.AddItem tmp +“=”+ Str(n)

  End If

  {#blank#}3{#/blank#}

 Next i

 End Sub

Dim strA As String, strB As String

strA = "hongda"：strB = ""

For i = 1 To Len(strA) * 2

If i / 2 = Int(i / 2) Then

strB = strB + Chr(Asc(Mid(strA, (i - 1) Mod Len(strA) + 1, 1)) + 2)

End If

Next i

该程序段运行后，变量strB的值是（  ）