Dim m2 As String

Private Sub Command1Click()

Dim flag(1 To 26) As Boolean

Dim num As Integer,t As Integer

Randomize

num = 1

Text3.Text = " "

For i = 1 To 26

    flag(i) = False

Next i

Do While num <= 26

    x = Int(Rnd * 26) + 97

          ①      

    If  flag(t) = False Then

    m2 = m2 + Chr(x)

    num = num + 1

      ②       

    End If

Loop

Text3.Text = m2

End Sub

Private Sub Command2Click()

Dim s As String， m As String， result As String

Dim k As String， c As Integer

s = Text1.Text

m = "abcdefghijklmnopqrstuvwxyz"

For i = 1 To Len(s)

    k = Mid(s, i, 1)

    If  k >= "A" And k <= "Z"  Then

    k = Chr(Asc(k) + 32)

    End If

    c = 1: continue = True

    Do While       ③       

    If k = Mid(m, c, 1) Then

    continue = False

    End If

    c = c + 1

    Loop

   ④     

Next i

Text2.Text = result

End Sub

程序①处的代码是{#blank#}1{#/blank#}

程序②处的代码是{#blank#}2{#/blank#}

程序③处的代码是{#blank#}3{#/blank#}

程序④处的代码是{#blank#}4{#/blank#}

  i=1:j=10

  Key=Val(Text1．Text)

    If a(m)=Key Then Exit Do      ‘Exit Do表示退出循环

    If Key Mod 2=1 And a (m)Mod 2=0 Then

    ElseIf Key Mod 2=0 And a(m)Mod 2=1 Then

Else

End If

  Loop

  If i>j Then s=“没有找到!”Else s=“位置：”+Str(m)

  Text2.Text=s

  上述程序中方框处可选语句为：

    ①i=m+1

    ②j=m-1

    @If Key<a(m)Then j=m-1 Else i=m+1

则(1)(2)(3)处语句依次是（  ）

Dim d(1 to 10) as Integer

n=10 : count = 0

For i = 1 To n

count = count + 1

If               Then

Label1.Caption = “顺序查找在数组的第” & i & “位找到了” & v

Exit For

End If

Next i

If                Then

Label1.Caption = “顺序查找没有找到” & v

End If

实现上述功能的VB程序如下，请回答下列问题：

t=“”: i=0 : j=9 : key=62: f=False

Do While i<=j And Not f

    m=Fix((i+j) / 2)

    t=t+Str(rn)

    If a(m)=key Then

        f=True

    Elself a(m) > key Then

         i=m+1

         t=t+“→”

    Else

        j=m-1

        t=t+“←”

    End If

Loop

数组元素a⑹到a⑼的值依次为“99, 94, 90, 87, 78, 70, 63, 56, 45, 36”,执行该程序段，t的值是（  ）

import random

a = [1,3,4,6,6,6,9,9,11,12]

key = random.randint(2,5) * 2

i,j = 0,9

while i <= j :

    m = (i + j) // 2

    if key < a[m]:

        j = m - 1

    else:

        i = m + 1

print(j)

执行该程序段后，输出的结果不可能是（   ）

A ．2                  B ．3                  C ． 5                  D ． 7