对窗体编写如下事件过程: Private Sub Form MouseDown(Button As Integer,Shift As Integer, _x As Single, Y As Single) If Button=2 ThenPrint "AAA" End If End Sub Private Sub Form MouseUp (Button As Integer,Shift As Integer,_x As Single,Y As Single)Print "BBB" End Sub 程序运行后,如果单击鼠标右键,则输出结果为 ______。
A.AAA BBB
B.BBB
C.AAA AAA
D.BBB