单项选择题

在窗体上画一个命令按钮和两个文本框,其名称分别为Command1、Text I和Text2,在属性窗口中把窗体的KeyPreview属性设置为True,然后编写如下程序:
  Dim S I As String, S2 As String
  Private Sub Form Load()
  Text 1 .Text=""
  Text2.Text=""
  Text 1.Enabled=False
  Text2.Enabled=False
  End Sub
  Private Sub Form_ KeyDown(KeyCode As Integer, Shift As Integer)
  S2=S2&Chr(KeyCode)
  End Sub
  
  Private Sub Forin_ KeyPress(KeyAscii As Integer)
  S1=S1&Chr(KeyAscii)
  End Sub
  Private Sub Command l Click
  Text l .Text=Sl
  Text2.Text=S2
  S1=""
  S2=""
  End Sub
  程序运行后,先后按“a”、“b”、“c”键,然后单击命令按钮,在文本框Textl和Text2中显示的内容分别为()

A.abc和ABC
B.空白
C.ABC和abc
D.出错