实现上述功能的VB程序如下，请回答下列问题：

Dim num As Integer         ‘变量num存储数据库实际的记录数

Dim book(1 to 5 000)As String

Dim content(1 To 5 000)As String，content1(1 To 5 000)As String  ‘存储类别内容

Dim sales(1 To 5 000)As Long，sales1(1 To 5 000)As Long     ‘存储销售量

Private Sub Form Load( )

  Dim conn As New ADODB．Connection，rs As New ADODB．Recordset

  Dim strSQL As String

  conn. ConnectionString="Provider=Microsoft. ACE. OLEDB. 12. 0; Data Source="＆App. Path&"＼major. accdb"

  conn. Open

  strSQL="SEl．ECT*FROM count"

  Set rs．ActiveConnection=conn

  ‘从数据表中读取图书类别、类别内容、销售量分别存储到数组book、content、sales中

  ‘数据库实际读取的记录数存储在变量num中

  ‘代码略

End Sub

 Private Sub Command1_Click()

  Dim m As String，n As String，c As Integer，s As Long

  Dim i As Integer，j As Integer，k As Integer

  List1．Clear

  c=0：s=0

  m=Text1．Text

  For i=l To num    ‘将符合的类别内容、销售量重新存储到数组content1、sales1中

    If m=book(i)Then

        c=c+1

        content1(c)=content(i)

        sales1(c)=sales(i)

                              ‘①

    EndIf

  Next i

  For i=1 To                ‘②

    List1．AddItem content1(i)&"  "&Str(sales1(i))

  Next i

  Text2．Text=Str(s)

End Sub

实现上述功能的VB程序如下。

Dim a(1 To 8) As Integer

Dim n As Integer

Private Sub Form_Load()

a(1) = 30: a(2) = 47: a(3) = 30: a(4) = 72

a(5) = 70: a(6) = 23: a(7) = 99: a(8) = 24

n = 8

For i = 1 To 8

List1.AddItem str(a(i))

Next i

End Sub

Private Sub Command1_Click()

Dim i As Integer, j As Integer, k As Integer

Dim pos As Integer

Dim s As String

s = Text1.Text

pos = Val(Text1.Text)

For i = 1 To n - 1

For j = n To i + 1 Step -1

If a(j) < a(j - 1) Then

                       '改错

a(j - 1) = a(j)

a(j) = k      

'如果pos位置的数据参与交换，则更新pos值，记录pos变化位置

If pos = j Then

pos = j - 1

s = s + "→" + Str(pos)

        elseif        ②           then

pos = j

s = s + "→" + Str(pos)

End If

End If

Next j

Next i

Label1.Caption = "位置变化情况：" + s

List2.Clear

For i = 1 To n

List2.AddItem Str(a(i))

Next i

End Sub

s=“26170534”:n=Len(s):y=“”

For i=1 To n

 ch(i)=Mid(s, i, 1)

Next i

For i=1 To n

 k=i

 For j=i To n Step 2

  If ch(j)< ch(k) Then k=j

 Next j

 If k <> i Then t=ch(k): ch(k)=ch(i): ch(i)=t

 y=y & ch(i)

Next i

Label1.Caption=y

该程序段运行后，标签Label1中显示的内容是（  ）

For i=1 To ①    

  k=i

  For j=i+1 To n-i+1

If a(k)>a(j) Then k= ②    

  Next j

  If k<>i Then t=a(k):a(k)=a(i):a(i)=t For j= ③      

    If a(j)<a(j+1) Then a(j)=a(j)+a(j+1) : a(j+1)=a(j)-a(j+1):a(j)=a(j)-a(j+1) Next j

Next i

上述程序段3个划线处的表达式分别为（  ）

For i=1 To n-1

    For j=________

        If a(j)<a(j -1) Then

            t=a(j): a(j)=a(j-1): a(j-1)=t

        End If

    Next j

Next i

为了使此程序段能实现数组a中的数据升序排列，则划线处应填入的代码是（   ）。

Const n = 100

Dim a(n) As Integer

Private Sub Form_Load()

′产生n个2位正整数，并显示在文本框Text1中，代码略

End Sub

Private Sub Command1_Click( )

    Dim i As Integer, j As Integer, left As Integer

    Dim right As Integer, m As Integer, t As Integer

    i = n-1

    Do While i > = 1

        ________

        right = n

        t = a(i)

        Do While left < = right

            m = Int((left + right)/2)

            If a(m) = t Then right = m: Exit Do

            If a(m) < t Then

                left = m + 1

            Else

                right = m-1

            End If

        Loop

        For j = i To right-1

            a(j) = a(j + 1)

        Next j

        ________________

        i = i-1

        s = “”

        For j = 1 To n

            s = s + Str(a(j))

        Next j

        List1.AddItem s

    Loop

End Sub