哪个地址表示子网内所有的参与多播的路由及主机______
A.224.0.0.1 B.224.0.0.5 C.224.0.0.6 D.224.0.0.9
参考答案:B
酸性蓄电池均衡充电的方法有哪两种?
有以下程序 #include <iostream> using namespace std; class Base int a; public: Base(int x) a=x; void show() cout<<a; class Derived : public Base int b; public: Derived(int i) :Base(i+1),b(i) void show() cout<<b; ; int main () Base b(5),*pb; Derived d(1); pb=&d; pb->show (); return 0; 运行后的打印结果是______。