Private Sub Command1_Click()

Text1.Text = f(3)

End Sub

Function f(x As Integer) As String

If x = 1 Then  f = 1  Else  f = f(x - 1) + 2

End Function

运行程序并点击按钮Command1后，文本框Text1中显示的内容是（   ）

  Function f(n As Integer)As Long

    Text1．Text=Trim(Str(n))+Text1．Text             ‘函数Trim的作用是去掉字串首尾空格

    If n=1 Then

       f=1

    Else

       f=3*f(n＼2)

    End If

  End Function

  Private Sub Command1_Click()

    Text1．Text=“”

    Text1．Text=Trim(Str(f(8)))+Text1．Text

  End Sub

单击按钮Command1后，文本框Text1中显示的值是（  ）

请完善下列程序代码：

Function prime(x As Integer) As Boolean ’此函数判断x是否为质数

  prime = True

  For i = 2 To Int(Sqr(x))

    If {#blank#}1{#/blank#} Then prime = False: Exit For

Next i

End Function

Private Sub Command2_Click()

Dim a As Integer, b As Integer

Dim n As Integer

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

For a = 2 To n \ 2

b = n - a

If {#blank#}3{#/blank#} Then

      List1.AddItem Str(a) + "  " + Str(b) + "  " + Str(n)

End If

          Next

End Sub

Do While i <= 5

If i = 1 Or a(i - 1) <= a(i) Then i = i + 1

Else

t = a(i): a(i) = a(i - 1): a(i - 1) = t i = i - 1

End If Loop

数组元素a(0)到a(8)的初始值依次为“0,4,7,3,5,1,8,6,2”。执行该程序段后，数组元素a(1)到a(8)的值分别是

Dim a(4) As Integer

Private Sub Command1_Click()

 Dim s As String

a(1)=10:a(2)=30:a(3)=20:a(4)=40

 s=doit(4)

 Label1.Caption=s

End Sub

Function doit(k As Integer) As String

 If k=1 Then

  doit=Str(a(1))

  Else

  doit=doit(k-1) & Str(a(k))

 End If

End Function

程序运行后,标签Label1中显示的内容是（  ）