单项选择题在Visual Basic中最基本的对象是 ______，它是应用程序的基石。
单项选择题在窗体上画一个命令按钮，然后编写下列程序：Private Sub Command1 click( )Dim a As Single，b As Singlea=6:b=2RC a，bPrint a，bEnd SubSub RC(x As Single，y As Single)i=xx=i yy=i Mod yEnd Sub
