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

Do While i <= j

       m = (i + j) \ 2

       If a(m) = Key Then text1.Text = "查找成功": Exit Do

       If Key < a(m) Then j = m - 1

       If Key > a(m) Then i = m + 1

Loop

i=1:j=7:x=45

Do While i <= j

    m = (i + j) \ 2

    If a(m) = x Then Exit Do    ‘Exit Do 退出 Do 循环

    If a(m) > x Then

        j = m - 1

    Else

        i = m + 1

    End If

Loop

执行完上述代码后，根据最终变量值判断下列表达式，其中成立的是（  ）

Dim a(1 To 6)As Integer

Dim i As Integer,j As Integer,Key As Integer,m As Integer

a(1)=11:a(2)=22:a(3)=33: a(4)=44:a(5)=55:a(6)=66

i=1:j=6:p=0:Key=23

Do While i<=j

p=p+1

  m=(i+j)\2

  If j Mod 2=0 Then m=m+1

  If a(m)=Key Then Exit Do

  If Key<a(m) Then j=m-1

Else i=m+1

Loop