【多选题】Which are syntactically valid statement at//point x? class Person { private int a; public int change(int m) { return m; } } public class Teacher extends Person { public int b; public static void main...
【简答题】下列程序的执行结果为【 】。 include <iostream. h> class Point { public: Point(double i, double j) { x=i; y=j;} double Area() const { return 0.0;} private: double x, y; }; class Rectangle: public Point { public: Re...