填空题

下面程序的输出结果为：Base:: fun，请将程序补充完整。
#include ＜iostream.h＞
class Base
public:
【12】 fun()cout＜＜"Base::fun"＜＜end1:
class Derived : public Base
public:
【13】 fun() cout＜＜"Derived::fun"＜＜end1;
;
int main() Base a,*pb;
Derived b;
pb = &b;
pb-＞fun();
return 0;