请回答下列问题：
Private Sub Command1_Click ()
Dim s As String, ch As String, flag As Boolean
Dim ch2 As String, res As String, i As Integer
s=Text.Text：res=“”
①
Do While＜= Len (s)
flag= False
ch= Mid (s, i, 1)
If i= 1 And ch＞=“a”And ch2＜=“z”Then
ch= Chr (Asc(ch)-32)′小写字母转换为大写字母
End If
If ch=“.” Or ch=“？” Then flag=True
ch2= Mid（s，i+1. 1）
If flag And ch2＞=“a”And ch2＜=“Z”Then
ch2= Chr (Asc(ch2)-32)′小写字母转换为大写字母
res= ②
i=i+2
Else
i=i+1
res=res+ch
End If
Loop
Text2. Text=res
End Sub
① ②
