Function fac(n As Integer) As Long

    fac = 1

    For i = 1 To n

fac = fac * i

    Next i

End Function

Private Sub Command1Click()

Dim s  As Long, j As Integer

For j = 1 To 10

Next

Text1.Text = Str(s)

End Sub

 方框中的正确语句是：（   ）

空白矩形框中应该填入的是（   ）

程序界面如下图所示，在Text1中输入原始字符串，在Text2中输入需要改变的字符，单机“改变”按钮后，在Text3中输出处理后的结果。程序代码如下：

Private Sub Command1Click()

Dim s As String, result As String, k As String

Dim zs As String, n As Integer

result = ""

s = Text1.Text

k = Text2.Text

For n = 1 To Len(s)

         ①      

  If zs = k Then

     If Asc(zs) >= 65 And Asc(zs) <= 90 Then

        zs = Chr(Asc(zs) + 32)

     ElseIf Asc(zs) >= 97 And Asc(zs) <= 122 Then

        zs = Chr(Asc(zs) - 32)

     End If

  End If

        ②       

Next n

        ③      

End Sub

在程序①、②、③划线处，填入适当的语句或表达式，把程序补充完整:

程序中①划线处应填入{#blank#}1{#/blank#}。

程序中②划线处应填入{#blank#}2{#/blank#}。

程序中③划线处应填入{#blank#}3{#/blank#}。

Private Sub Command1_click()

Dim s as integer,I as integer

S=0

For i=1 to 20 step 3

      s=s+(-1)^i*i

Next i

Label1.caption=str(i)

Label2.caption=str(s)

End Sub

Dim a(1 To 10) As Integer，i As Integer，j As Integer

a(1)=1

a(2)=1

For i=3 To 5

a(i)=1

For j=i-1 To 2 Step -1

a(j)=a(j)+a(j-1)

Next j

Next i

Text1.Text=Str(a(3))

该程序段运行后，在文本框Text1中显示的内容是(  )

图1

图2

图3