声明类Student，包含3个成员变量：name、age、score， 要求可以通过 new Student("张三", 22, 95)

　　 * 的方式创建对象，并可以通过set和get方法访问成员变量-Statement class Student, consists of three member variables: name, age, score, requirements can be achieved by the new Student (" zhang ", 22, 95)

* way to create objects, and can be set and get methods to access member variables