执行下列程序的输出结果是______: #include<iostream> using namespace std; class TestClass1 { public: void fun1(){cout<<"TestClass1\n";} virtual void fun2(){cout<<"TestClass1\n";} }; class TestClass2:public TestClass1 { public: void fun1(){cout<<"TestClass2\n";} void fun2(){cout<<"TestClass2\n";} }; void f(TestClass1&b)<b.fun1();b.fun2();} int main() { TestClass2 obj; f(obj); return 0; }