[填空题] 在窗体上画一个名称为Timer1的计时器控件,其Enabled属性值为False,Interval属性值设为100。要求程序运行后,当鼠标在窗体上移动时,沿鼠标经过的轨迹画出一系列半径为100的小圆。其效果如图所示。以下是实现上述功能的程序,请填空。Dim a As Integer, b As IntegerPrivate Sub Form_()(Button As Integer,Shift As Integer,X As Single,Y As Single)a=Xb=YTimer1.Enabled=()End SubPrivate Sub Timer1_timer( )Form1.Cirle(a,b),100 ‘以(a,b)为圆心画一个半径为100的圆End SubPrivate Sub Form()(Button As Integer,Shift As Integer,X As Single,Y As Single)