请在下面代码中加入监听器语句。
import java.awt.*；
import java.applet.Applet；
public class Simple extends Apple implements MouseListener

StringBuffer；
public void init()

//监听器语句
buffer=new StringBuffer()；
addItem("initializing…")；

public void moseEntered(MouseEvent event)

public void moseExited(MouseEvent event)

public void mosePressed(MouseEvent event)

public void moseReleased(MouseEvent event)

public void moseClicked(MouseEvent event)

addltem("click!…")；