C++程序填空题（初学者）

#include<iostream.h>

     class  Point

     {  public:

            Point( double a,double b,double c)

             {  ___________________   ①}

            double Getx(){  return X ; }

            double Gety() {  return Y ;}

            double Getz() { return Z ;}

      private:

            ________________  ②

      protected:

            _______________   ③

};

class Line:__________④ Point

{ public:

   Line(double a, double b,double c,double d)_________⑤

   { __________________________  ⑥}

   void show( )

   {  cout<<Getx()<<endl;

      cout<<Gety()<<” “<<Y<<endl;

      cout<< Getz()<<” “<<Z<<endl;

      cout<<K<<endl;  }

private:

  double  K;

};

void main( )

{ Line obj(1.2 , 3.4 , 5.6 , 7.8);

             obj.show( );

          }