（单项选择题）填空题：在Visual Basic中，如何编写事件过程以响应鼠标右键点击窗体时显示快捷菜单？
A．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) If Button=2 Then PopupMenu Bs, 2 End Sub
B．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) PopupMenu Bs End Sub
C．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) PopupMenu Bs, 0 End Sub
D．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) If (Button=vbLeftButton) Or (Button=vbRightButton) Then PopupMenu Bs End Sub
正确答案是。
- A．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) If Button=2 Then PopupMenu Bs, 2 End Sub
- B．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) PopupMenu Bs End Sub
- C．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) PopupMenu Bs, 0 End Sub
- D．Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) If (Button=vbLeftButton) Or (Button=vbRightButton) Then PopupMenu Bs End Sub
提问：
请问在Visual Basic中，如何通过事件过程来实现鼠标右键点击窗体时显示快捷菜单？这个问题的重点是考察什么知识点？这个章节的主要内容是什么？
复习要点：
理解Visual Basic中的事件处理和菜单操作，特别是如何通过MouseDown事件和PopupMenu方法来实现快捷菜单的显示。重点复习事件驱动编程和用户界面交互。
查阅资料方向：
查阅关于Visual Basic中事件处理和菜单操作的资料，特别是MouseDown事件和PopupMenu方法的使用。