单选题 在窗体上画一个名称为Command1的命令按钮，然后编写如下事件过程：
Private Sub Command1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = 2 Then
Print "ABCD";
Else
Print "DDDD";
End If
End Sub
Private Sub Command1_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
Print "EFGH"
End Sub
程序运行后，单击命令按钮，输出结果是______。