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

{

G．raphics 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 ) { }

}