使用VC6打开考生文件夹下的工程test25_1，此工程包含一个源程序文件test25_1.cpp，但该程序运行有问题，请改正程序中的错误，使程序的输出结果如下： privatel from derived1:30 privatel from derived2:30 源程序文件test25_1.cpp清单如下： /***************found******************/ include＜iostream.h＞ class base protected: int privatel; public: base(int p)privatel=p; ; /****************found*******************/ class derived1:public base public: derivedl(int p1):base(p1); int get_private()return private1; class derived2:virtua1 public base public: derived2(int p2):base(p2); int get_private()return private1; ; class derived12:public derived1,public derived2 public: /****************found*******************/ derived12(int p1,int p2,int pb):derived1(p1), base(pb), derived2(p2); ; void main() derived12 d(10,20,30); cout＜＜"privatel from derived1:"＜＜d.derived1::get_private(); cout＜＜"\nprivatel from derived2:"＜＜d.derived2::get_private(); cout＜＜endl;