把其中代码Static x As Integer修改为DIM x As Integer，再观察结果是否有变化，为什么？
Private Sub Command1_Click()
 Static x As Integer
 x = 10
 y = 5
 y = f(x)
 Print x; y
End Sub
Public Function f(x As Integer)
 Dim y As Integer
 x = 20
 y = 2
 f = x * y
End Function