输入学生的姓名，在组合框中选择班级，点击确定可加入列表框，不可重复加入。选中列表框中的内容可点击删除按钮删除。-Enter the student' s name, choice of classes in the combo box, click OK to join the list box, adding non-repeatable. Select the contents of the list box click the Delete button to delete.