定义一个教师类，由教师类派生出讲师、副教授、教授类。教师的工资分别由基本工资、课时费和津贴构成。假设讲师、副教授、教授的基本工资分别为800、900、1000元，课时费分别为每小时40、45、50元，津贴分别为1300、1800、2300。定义虚函数来计算教师的工资，并通过主函数来进行验证。-The definition of a class teacher, class teacher derived lecturer, associate professor of the class. Teachers'　salaries are composed of a basic salary, fees and allowances class. Suppose lecturer, associate professor of basic salary respectively 800,900,1000 yuan, respectively, 40,45,50 class fee per hour, respectively 1300,1800,2300 allowance. Definition of virtual function to calculate the salaries of teachers, and authenticated by the main function.