请在下列程序代码的基础上按照要求设计该程序, 完善程序中的划线部分。

Dim n As Integer, a1 As Integer, a2 As Integer, a3 As Integer

Function f(x) As Boolean

f = True

      For i = 2 To Sqr(x)

         If x Mod i = 0 Then      ①     

Next i

End Function

Private Sub Command1_Click()

n =      ②       

For a1 = 2 To n

 For a2 = a1 To n

  For a3 = a2 To n

   If     ③      And f(a1) And f(a2) And f(a3) Then

    List1.AddItem (Str(a1) + " " + Str(a2) + " " + Str(a3))

   End If

  Next a3

 Next a2

Next a1

End Sub

其中①处填入{#blank#}1{#/blank#}；②处填入{#blank#}2{#/blank#}；③处填入{#blank#}3{#/blank#}

  k = 0                 '用来计数

  Max = 600             '指定范围600以内

  n = 9                                  

  Do While n <= Max

  Loop

  Label1.Caption = Str(Max) & "范围内满足问题的数有" & Str(k) & "个"

End Sub

方框中的代码由以下五部分组成：

① n=n+7

② k = k + 1

③ List1.AddItem Str(n)

④ End If

⑤ If n Mod 3 = 2 And n Mod 5 = 3 Then

代码顺序正确的选项是（  ）

Dim a(1 to 5) as Integer, i as Integer, c as Integer

a(1) = 2 : a(2) = 1 : a(3) = 3 : a(4) = 4 : a(5) = 5

c = 0

For I = 3 to 5

If a(i - 2) + a(i - 1) = a(i) Then c = c + 1

Next i

Text1.Text = Str(c)

该程序运行后，文本框text1中显示的内容是（  ）

实现上述功能的VB代码如下：

Private Sub Command1_Click() Dim a(0 To 4) As String Dim b(0 To 4) As Integer

Dim s As String, r As String

Dim i As Integer, j As Integer, k As Integer, c As Integer, n As Integer

List1.Clear

s = Text1.Text :   n = Len(s)

If         Then    '选填 Label1.Caption = "数据输入有误！"

Exit Sub   '退出 End If

For i = 0 To n - 1

a(i) = Mid(s, i + 1, 1) b(i) = 0

Next i c = 0

For i = 1 To n ^ n r = ""

For j = 0 To n - 1

Next j

c = c + 1 List1.AddItem r k = 0

b(k) = b(k) + 1

Do While b(k) = n And k < 4 b(k) = 0

b(k) = b(k) + 1 Loop

Next i

Label1.Caption = "构造字符串的方法共计" + Str(c) + "种。" End Sub

Function test(s As String) As Boolean ‘用于判别是否存在重复的字符，代码略

‘若无重复，则返回True，否则返回False

End Function

请回答下列问题：

最佳方案:初始时所有人聚集在2号房间，花费的能量和:7*0+8*1+6*2+4*3+4*4=48。为了解决这个问题，小明编写了一个VB程序。在窗体加载时，从数据库中读取N的值和编号为1到N的房间的居住人数，人数存储在数组a中。点击窗体上的按钮Command1，程序枚举每一种方案(不同的初始房间)，计算该方案的能量和，在文本框Text1中输出最优方案的初始房间编号，在文本框Text2中输出最小能量和。

实现上述功能的VB代码如下，请在划线处填入合适代码。

Dim a(1 To 100) As Integer ’依次存储编号为1到100的房间的居住人数

Private Sub Form_Load()

‘本过程从数据库中读取N的值和每个房间居住人数，存储在数组a中

‘代码略

End Sub

Private Sub Command1_Click()

Dim i As Integer, j As Integer, w As Integer, k as Integer

Dim t As Long, ans As Long

k=0 : ans = 32767     ‘ans初始化为最大的Integer数据

For i = 1 To n

 t = 0

 For j = 0 To n - 1

    w={#blank#}1{#/blank#}

    If w = 0 Then w = n

    t={#blank#}2{#/blank#}

 Next j

 If t < ans Then

    k= i

    ans = t

 End If

Next i

Text1.Text = Str (k)    ‘起始房间编号

Text2.Text ={#blank#}3{#/blank#}

End Sub

Private Sub Command1_Click()

    List1.clear

    Dim a As Integer

    For i = 1 To 1000

        s = 0

        i= Len(Str(i)) - 1

        For j = 0 To i - 1

            a =           

            s = s + a ^ 3

        Next j

        If i = s Then

            List1.AddItem i

        End If

    Next i

End Sub

横线处应填写 （   ）