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#}

实现上述功能的 VB 程序如下，请回答下列问题：

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

i=1 : j=8 : t=0

key=Int(Rnd()*7)+14

Do While i<=j

   m = Int((i + j )/2)

   t=t+1

 if a(m)=key Then

      Exit Do else

      If a(m)>key Then  j=m-1

Else  

         i=m+1

End if

   End if Loop

数组元素 a(1)到 a(8)的值依次为“2,11,14,15,18,19,20,22”，该程序段运行结束后，变量t的最大值可能是（  ）

i = 1: j = 7: s = ""

key = Int(Rnd * 100)

Do While i <= j

   m = (i + j) \ 2

   If key = a(m) Then

      s = s + "M": Exit Do    'Exit Do 表示退出循环

   ElseIf key < a(m) Then

      j = m - 1: s = s + "L"

   Else

      i = m + 1: s = s + "R"

   End If

Loop

Text1.Text = s