[单项选择题] 执行下面的程序，单击窗体后在窗体上显示的结果是 ______。Private Sub form_ Click() Dim Str1 As St

[单项选择题] 执行下面的程序，单击窗体后在窗体上显示的结果是 ______。Private Sub form_ Click() Dim Str1 As String, Str2 As String Dim Str3 As String, I As Integer Str1 = "e" for I = t To 2 Str2 = Ucase (Str1) Str1 = Str2 & Str1 Str3 = Str3 & Str1 str1 = Chr (Asc(Str1) + I) Next I Print Str3End Sub

A．EeFF

B．eEfF

C．EEFF

D．eeFF

A

本题的难点是熟悉下列字符串处理内部函数：Asc(x)为求单个字符ASCII代码函数，Chr[＄](x)返回以x为ASCII代码值的字符，Ucase[＄](x)将x字符串中所有小写字符改为大写字符。