#include using namespace std; class A{ public: void DoPublic(){cout< protected: void DoProtected(){ cout< } private: void DoPrivate(){cout< } }; class B: public A { public: void DoPublic(){ DoProtected(); //语句(1) DoPrivated(); //语句(2) } }; int main() { A a; B b; a.DoPublic();//语句(3); b.DoProtected(); //语句(4) return 0; } 以下说法正确的是: