在main函数中通过new实例化ChildLabourer类的对象，并通过该对象调用worker及children类中的成员函数，最后销毁该对象，体会多继承的继承特性及构造函数及析构函数的执行顺序。(Through the new object instantiation of class ChildLabourer in the main function, and the function of the object and call the worker member of the chi