实现上述功能的VB程序如下，但加框处代码有错，请改正。

Dim a(0 To 20)As Integer，d(0 To 20)As Integer

Dim n As Integer

Private Sub Command1_Click()

‘产生n个[10，99]之间的随机整数，存储在a(0 To n-1)中，同时显示在List1中，代码略

End Sub  

Private Sub Command2_Click()

    Dim i As Integer  

    n=Val(Text1．Text)   

    For i=0 To n-2    

      For j=i+1 To n-1  

        If     Then            ‘(1)

          temp=a(i)：a(i)=a(j)：a(j)=temp

        End If

     Next j

Next i 

If n Mod 2<>0 Then  d(n＼2)=a(n-1)  ‘个数为奇数，最小值放中间位置

    For i=0 To n＼2—1

    d(i)=a(i*2)

=a(2*i+1)               ‘(2)

Next i

  ‘在列表框List2中输出数组d，代码略

  End Sub

Dim a(1 To 1000) As Single, b(1 To 1000) As Integer Private Sub Form_Load()

Randomize    '生成 1000 个随机数 For i = 1 To 1000

       ①   '产生随机数，保留二位小数

   b(i) = 1                                           '初始排位为 1

   List1.AddItem "a(" & i & ")=" & a(i) Next i

End Sub

Private Sub Command1_Click()

Dim ks As Integer, js As Integer

ks = Val(Text1.Text)  

js = Val(Text2.Text)

For i = ks To js

  For j = ks To js

    If  Then b(i) = b(i) + 1         ②

  Next j

Text1  Text2

  List2.AddItem "a(" & i & ")" & "在 a(" & ks & ")~a(" & js & ")中排位为" & b(i) Next i

End Sub

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

m = (1 + n) \ 2       ‘n为数组元素的个数，m为数组中间位置元素的下标

For i = 1 To n

    If a(i) < a(m) Then t = a(i): a(i) = a(m): a(m) = t

Next i

p = m: q = m

For i = 1 To n - 2

    If i Mod 2 = 1 Then

        k = q + 1: q = q + 1

    Else

        k = p - 1: p = p - 1

    End If

    pos = k

    For j = 1 To n

        If And a(j) < a(k) Then k = j

    Next j

    If pos > k Then

        t = a(pos): a(pos) = a(k): a(k) = t

    End If

Next i

上述程序段方框处的代码为（  ）

For i = 1 To n -1

       ①  

    For j = i To n-1

        If a(j) < a(k) Then k = j卷（信息技术）（一） 第4页（共 8 页）

    Next j

    s = a(i): a(i) = a(k): a(k) = s

Next i

则代码①中的语句为（    ）

a=[27,5,25,36,78]

f=[False]*5

i=0

while i<4 and not f[i]:

    for j in range(4, i, -1):

        if a[j]<a[j-1]:

            a[j], a[j-1]=a[j-1], a[j]

            f[i]=True

    i+=1

执行该程序段后，数组f中值为True的元素个数是（   ）