下列操作或仪器的选用正确的是 [     ]

A.

B.

C.

D.

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( )constreturn 0.0;
private:
double x,y;
;
class Rectangle:public Point

public:
Rectangle(double i,double J,double k,double 1);
double Area( )const(return w*h;
private:
double w,h;
;
Rectangle::Rectangle(double i,double j,double k,double 1):Point(i,j)

w=k;h=l;

void fun(Point&s)

cout＜＜s.Area( )＜＜endl;

void main( )

Rectangle rec(3.0,5.2,15.0,25.0);
fun(rec);