Private Sub Command1_Click()

  Dim a(0 To 5) As Integer

  Dim i As Integer               ’①

  a(0) = 1                      '②

  For i = 1 To 5

    a(i) = 2 * a(i - 1) + 1          '③

  Next i

  Text1.Text = Str(a(6))         '④

End Sub

s=“7218634594” : n=Len(s): c=0

For i=1 To n-1

  a(i)=Val(Mid(s, i, 2))

Next i

For i=1 To n-2 Step 2

  k=i

  For j=i+2 To n-1 Step 2

    If a(j) < a(k) Then k=j

  Next j

 If k <> i Then

   t=a(i): a(i)=a(k): a(k)=t: c=c+1

 End If

Next i

Text1.Text=Str(c)

该程序段运行后，Text1中显示的内容是（  ）

For i=1 To 3

 For j=8 To i+1 Step-1

  If a(j) < a(i) Then

   t=a(j): a(j)=a(i): a(i)=t

  End If

 Next j

Next i

数组元素a(1)到a(8)的值依次为“35， 18， 14， 20， 30， 15， 28， 26”，运行该程序段后，a(5)到a(8)的值依次是（  ）

实现上述功能的VB程序如下，但加框处代码有错，请改正。

Const n = 10    ‘数组元素的总数

Dim a(1 To n) As Integer

Private Sub Form_Load()

‘该过程对数组a进行赋值,并在列表框List1中显示，代码略

End Sub

Private Sub Command1_Click()

Dim i As Integer, j As Integer,flag(1 To n) As Boolean

‘flag(i)记录第i个元素是否重复出现

For i = 1 To n      ‘flag(i)=true开始假设都只出现1次

 flag(i) = True

Next i

For i = 1 To n

 If flag(i) Then

  For j = i + 1 To n

    If Then flag(i) = False: flag(j) = False    ‘①

  Next j

 End If

Next i

For i = 1 To n

  If Then List2.AddItem Str(a(i))    ‘②

Next i

End Sub

①{#blank#}1{#/blank#} ②{#blank#}2{#/blank#} 

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