阅读以下说明和JAVA2代码，将应填入(n)处的字句写在对应栏内。
【说明】
以下程序实现了利用鼠标任意移动该圆形的位置，仔细阅读代码和相关注释，将程序补充完整。
【代码6】
import java.awt.*;
import java.awt.event.*;
public class CIUSAMPLE extends Frame. implements MouseMotionListener, MouseListener
{
static CIUSAMPLE frm=new CIUSAMPLE ();
int x=70,y=60,posX=70,posY=60,dx,dy;
public static void main (String args[])
{
frm.setTitle ("Dragging a circle");
frm.setSize (200,150 );
(1)
frm.addMouseMotionListener (frm );
frm. setVisible (true );
}
public void mousePressed (MouseEvent e )
{
(2)
dy=e.getY () -posY;
}
public void mouseDragged (MouseEvent e )
{
(3)
y=e.getY () -dy;
if (dx＞0 && dx＜50 && dy＞0 && dy＜50 ) //如果指我落在正方形区域内
{
Graphics g=getGraphics ();
(4)
}
}
public void paint (Graphics g )
{
g.setColor (Color. pink ); // 设置绘图颜色为粉红
g.fillOval (x,y,50,50 ); //以基准点为图形的左上角绘出圆形
(5)
posY=y;
}
public void mouseMoved (MouseEvent e ) { }
public void mouseReleased (MouseEvent e ) { }
public void mouseEntered (MouseEvent e ) { }
public void mouseExited (MouseEvent e ) { }
public void mouseClicked (MouseEvent e ) { }
}