实现上述功能的VB程序如下：

Private Sub Command1_Click()  

Dim a(1 To 1000) As String   '数组a存储文中出现该指定单词(或字符串)的各个位置

Dim s As String, c As String ,ch As String

Dim n As Integer, max As Integer, i As Integer

s = Text1.Text 

c = Text2.Text

n = 0: Max = 0

For i = 1 To Len(s) - Len(c) + 1

    ch =     ①   

    If ch = c Then

        n = n + 1

        a(n) = i

        If n >= 2 Then

If a(n) - a(n - 1) - Len(c) > Max Then Max = a(n) - a(n - 1) - Len(c)

        End If

    End If

Next i

Text3.Text =     ②  

End Sub

以上程序段运行时，为了实现上述功能，划线处①和②应填入的代码分别为： 

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

实现上述功能的程序如下，请回答下列问题：

Private Sub Com1_Click( )  

Dim s As String

Dim flag As Boolean

Dim n As Integer， i As Integer

  s = Text1.Text

  _________     ‘①

  flag = True

  i = 1

  Do While i <= n \ 2

    If  Mid(s， i， 1) < >________________ Then      ‘②

       flag = False

       Exit Do       '退出Do循环

    End If

    i = i + 1

  Loop

  If flag Then

     Label2.Caption = s + "是回文字符串"

  Else

     Label2.Caption = s + "不是回文字符串"

  End If

End Sub

l=1: r=6

Key=Val(Text1.Text)

Do While l <=r

 m=Int((l+r) \ 2)

 If a(m)=Key Then

   ⑴  

  Exit Do

 Elself a(m) >=a(l) Then

   ⑵  

 Elself a(m) < a(l) Then

   ⑶  

 End If

Loop

上述程序中方框处可选语句为:

①If a(m) < Key And a(r) >=Key Then l=m+1 Else r=m-1

②Listl .AddItem “第”+Str(m)+“值是”+Str(a(m))

③If a(m) > Key And a(l) <=Key Then r=m-1 Else l=m+1

则(1)、(2)、(3)处语句依次是（  ）

def mypow(x,y=2):

    return x **y, x+y

    print( " hello" )

a,b=mypow(3,4)

print(a,b)

import math

def CircleArea(r):

    area=math.pi *r *r

    return area