有关下面C++代码的说法正确的是（ ）。
class Node{public: int Value; Node* Prev; Node* Next; Node(int Val, Node* Prv = NULL, Node* Nxt = NULL);}; Node::Node(int Val,Node*Prv,Node* Nxt){ this->Value = Val; this->Prev = Prv; this->Next = Nxt;} int main(){ Node firstNode = Node(10); firstNode.Next = new Node(100, &firstNode); firstNode.Next->Next = new Node(111, firstNode.Next);}