单项选择题语句ofstream f( TEMP.DAT , ios::app | ios::binary);的功能是建立流对象f,试图打开文件TEMP.DAT并与之连接,并且______
单项选择题对于类定义class A{public:virtual void func1(){}void func2(){}};class B:public A{public:void func1(){cout<< class B func1 <<endl; }virtual void func2(){cout<< class B func2 <<endl; }};下面正确的叙述是______