下列程序在调试时提示错误“块IF没有End If”，要使程序正常运行，则应该在 （填①或②）处添加语句     。
Private Sub Image3_Click(Index As Integer)
Timer1.Enabled = False
Image1.Picture = Image3(Index).Picture
If x =" Index" Then
Label1.Caption = "平手"
Command1.Visible = True
    ①  
Else
If x =" 1" And Index =" 2" Or x =" 2" And Index =" 3" Or x =" 3" And Index =" 1" Then
Label1.Caption = "您输"
Command1.Visible = True:Zxxk.Com
Else
Label1.Caption = "您赢"
Command1.Visible = True
End If
    ②     
End Sub

输入-1、7、8、9、-5，则输出 。

有如下VB程序段
m=a(1)
For t=2  to  15  step 2
If  a(t) > m  then  m=a(t)
Next t
该程序段执行后，变量t的值是（   ）

A．14

B．15

C．16

D．17

有如下VB程序段：
s = Text1.Text
t = 0: Sum = 0
For i = 1 To len(s)
c = Mid(s, i, 1)
If c >= "0" And c <= "9" Then
t = t * 10 + Val(c)
ElseIf c >= "a" And c <= "z" Then
Sum = Sum + t
Else
t = 0
End If
Next i
Text2.Text = Str(Sum)
在文本框Text1中输入“123aBc456”，执行程序段，文本框Text2中显示的内容是（   ）

A．456

B．654

C．579

D．123

写出算法执行结果