下列程序的输出结果是 ( ) #include using namespace std class A{ int a public: A():a(9){} virtual void print() const {coutclass B:public A{ char b public: B(){b= ‘S’} void print()const{coutvoid show(Aa&X){X,print()} int main() { Ad1*p Bd2 p=&d2 d1,print() d2,print() p->print() show(d1) show(d2) return 0}