设有如下程序： Prirate Sub Form_Click() Dim a As
Integer,b AS Integer a=20:b=50 p1 a,b
p2 a,b p3 a,b Print"a="；a,"b=";b
End Sub Sub p1(x As Integeh By Val y As Integer)
x=x+10 y=y+20 End Sub Sub
p2(ByVal x As Integer,y As Integer) x=x+10
y=y+20 End Sub Sub p3 (ByVal x As
Integer,ByVal y As Integer) x=x+10
y=y+20 End Sub
该程序运行后，单击窗体，则在窗体上显示的内容是：a= (11) 和b= (12)
。