[说明] 下面代码实现class C对class A和B的protected成员和public成员的调用。仔细阅读[代码5-1]、[代码5-2]，在 (n) 处写出正确的运行结果。 [代码5-1] #include ＜iostream.h＞ class A { private: int a1; protected: int a2; public: A ( int v1,int v2,int v3 ): a1 ( v1 ) ,a2 ( v2 ) ,a3 ( v3 ) {} int a3 }; class B : pubiic A{ private: int b1; protected: int b2; public: B ( int v1,int v2,int v3,int v4,int v5,int v6 ) : A(v1,v2,v3),b1 (v4),b2(v5),b3 (v6) {} int b3; }; class C : public B{ private: int c1; protected: int c2; public: int c3; C (int v1,int v2,int v3,int v4,int v5,int v6,int v7,int v8,int v9 ) : B ( v1,v2,v3,v4,v5,v6 ) ,c1 ( v7 ),c2 ( v8 ) ,c3 v9 void disp ( ) { cout ＜＜ "a2 in class C =" ＜＜ a2 ＜＜ endl; cout ＜＜ "a3 in class C =" ＜＜ a3 ＜＜ eudl; cout ＜＜ "b2 in class C =" ＜＜ b2 ＜＜ endl; tout ＜＜ "b3 in class C =" ＜＜ b3 ＜＜ endl; } }； [代码5-2] voidmain() { Cdemo(10,20,30,40,50,60,70,80,90)； cout＜＜"对象demo.a3="＜＜demo.a3< cout＜＜"对象demo.b3="＜＜demo.b3< cout＜＜"对象demo.c3="＜＜demo.c3< demo.disp( )； } [运行结果] 对象demo.a3＝ (1) 对象demo.b3＝ (2) 对象demo.c3＝ (3) a2 in class C＝ (4) a3 in class C＝ (5) b2 in class C＝ (6) b2 in class C＝ (7)