Private Sub Command1Click()

Dim a(1 To 4) As Integer

Dim i As Integer

   a(1) = 1

 For i = 2 To 4

   a(i) = 2 * a(i - 1) + 1

 Next i

List1.AddItem Str(a(i))

End Sub

Private Sub Command1_Click()

Dim  a  As  String

Dim  b  As  String

Dim  c  As  String

a = Text1.Text

b = Text2.Text

c = a + b

Label1.capton = c

End Sub

程序运行时，单击命令按钮command1，弹出如图所示的出错信息提示，此时程序正执行的语句是（   ）

请在划线处填入合适的代码

Private Sub Command1_Click()

  Dim s As String, k As Integer

  {#blank#}1{#/blank#}

  k = Val(Text2.Text)

  Label3.Caption=“对应的十进制数：”+Str(toD(s, k))

End Sub

Function toD(s As String, k As Integer) As Integer

  Dim ans As Integer, x As Integer

  ans = 0

  For i = 1 To Len(s)

    If Mid(s, i, 1) >= "A" And Mid(s, i, 1) <= "F" Then

      x = Asc(Mid(s， i, 1))- Asc(“A”)十 10

    Else

      x = Val(Mid(s, i, 1))

    End If

    {#blank#}2{#/blank#}

  Next i

  {#blank#}3{#/blank#}

End Function

Private Function f(x As Single, n As Integer) As Single

  If n ＝0 Then

    f ＝1

  Else

    If n Mod 2 ＝1 Then

      f＝x * f(x, n\2)

    Else

      f＝f(x, n\2) \x

    End If

  End If

End Function

Private Sub Command1_Click()

  Label1.Caption＝Str(f(4, 6))

End Sub

程序运行时，单击按钮Command1，标签Label1显示的内容是（  ）

k=1

while 1:

    k+=1