阅读下面程序段，SelectItem应用程序显示从文本域的组合框中进行选择，请在程序中的画线处添上正确的语句使得程序能够正确运行。 ... JTextField result = new JTextField(); JComboBox pick = new JComboBox (); public SelectItem() { super ('Select Item'); pick.addItemListener(this); pick.addItem('Navigtor'); pick.addItem('Internet Explorer'); pick.addItem('Opera'); pick.setEditable(false); result.setHorizontalAlignment(SwingConstants.CENTER); result, setEditable (false); pane.setLayout(new BorderLayout()); 【 】 pane.add(pick,'Center'); pane.add(result,'South'); setContentPane(pane); } public void itemStateChanged(ItemEvent evt) { Object source = evt.getSource(); if(source == pick) { Object newPick = evt.getItem(); result .setText(newPick.toString()+' is the selection.'); } repaint(); }