写出下面程序的执行结果：

#include<iostream>

using namespace std;

class B{

protected:

  int b;

public :

  B(int i){b=i+50;show( );}

  B( ){}

  virtual void show( ){cout<<"B::show( ) is called. b="<<b<<endl;}

};

class D:public B{

    protected:

      int d;

public :

  D(int i):B(i){d=i+100;show( );}

  D( ){}

  void show( ){cout<<"D::show( )is called. d="<<d<<endl;}

};

int main( ){D d1(108); return 0;}