下列Applet实现键盘事件处理，当一个键按下时，判断是否为26个英文字母，并输出该字母。选择正确的语

句填入横线处。 import java.applet.Applet; import java.awt.*; import java.awt.event.*; public class ex34 extends Applet { String str = ""; public void init() { addKeyListener (new KeyAdapter (} { ______ { char ch; ch = ke.getKeyChar(); if((ch ＞= 'a' && ch ＜= 'z') || (ch ＞= 'A' && ch ＜= 'Z')) str = "字母:"+ ch; else str "＞"不是字母"; repaint(); } }); requestFocus(); } public void paint(Graphics g) { g.drawString(str, 50, 50); } }

A．public void keyPress(KeyEvent ke)

B．public void keyTyped(KeyEvent ke)

C．public void keyTyped(Event ke)

D．public void keyPressing(KeyEvent ke)