关于运行结果的闪现问题（我用的是dev c++ 编译的）

include<iostream>
using namespace std;
class  box
{
       public:
       box(int x,int y,int z)
       {
               chang=x;
               kuan=y;
               gao=z;
       }
       virtual void show ()
       {
            cout<<chang<<"  "<<kuan<<"  "<<gao<<endl;
       }
       virtual ~box()
       {
             cout<<"基类清理"<<endl;
       }      
      
       protected:
       int chang;
       int kuan;
       int gao;
};
class box1:public box
{
      public:
      box1(int x,int y,int z,int u):box(x,y,z)
      {
            color=u;
      }
      virtual void show()
      {
           cout<<chang<<"  "<<kuan<<"  "<<gao<<"  "<<color<<endl;
      }
      virtual ~box1()
      {
              cout<<"派生类清理"<<endl;
      }        
      protected:
      int color;
};


int   main()
{
      box b(1,1,1);
      box1 bb(1,1,1,1);
      box *p;
      p=&b;
      p->show();
      p=&bb;
      p->show();
      system("pause");
      return(0);
      system("pause");//   我已经用了俩次system("pause")；希望能看清点可是，我还是看不到析构函数的输出语句？？？？？？
 
      
}