Private Sub Command1Click(   )

Dim n As Integer

Dim a(1 To 10) As Integer

n = Val(Text1.Text)

s = 1

For i = 1 To n

s = s * i

a(i) = s

List1.AddItem Str(a(i))

Next i

End Sub

n = 0 : m = 0

For  i = 1 To 100

     If  Rnd > 0.5  Then

        n = n + 1

     Else

     m = m + 1

Next  i 

……

小金仔细分析该程序段后，发现其中缺少了（   ）

Private Sub Command1_Click()

Dim sum As Double, x As Double

sum = 0

n = 0

For i = 1 To 5

x = n / i

n = n + 1

sum = sum + x

Next i

End Sub

该程序通过For循环计算一个表达式的值，这个表达式是（   ）

  s=Text1．Text

  List1．Clear

  Len1=Len(s)                            ‘①

  For i=l To len1                           ‘②

    For j=1 To len1-i                       ‘③

        List1．Addltem Mid(S，j，i)         ‘④

     Next j

   Next i

运行时发现未输出所有子串，则修改（  ）

图1

图2

Private Sub Command1_Click()

Dim d(1 To 8) As Integer

Dim i As Integer, s As Integer

d(1)=1

For i=2 To 10

    d(i)=d(i-1)*i

Next i

For i=1 To 5

    s=s+d(i)

Next i

Text1.Text = Str(s)

End Sub

程序运行时，单击命令按钮Command1后，将会出现的提示信息是（  ）