气管切开的部位一般在（）.

A.第1～2气管软骨环

B.第3～5气管软骨环

C.第6～7气管软骨环

D.第8～10气管软骨环

E.低于第10气管软骨环

请在下面代码中加入监听器语句 【15】 。
import java.awt.*;
import java.applet.Applet;
public class Simple extends Applet implements MouseListener

StringBuffer;
Public void init()

______//加监听器语句
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)

addItem("click!...");