C++新人，求师傅指导下

#include<iostream>
using namespace std;
class A
{
public:
A(int x,int y)
{
m_x=x;
m_y=y;
}
int Display()
{
cout<<"m_x="<<m_x;
cout<<"m_y="<<m_y;
}
private:
int m_x;
int m_y;
};
class B:public A
{
public:
B(int x,int y,int z):A(x,y)
{
m_z=z;
}
void Display()
{
cout<<"m_x="<<B.Display;
}
private:
int m_z;
};
int main()
{
B *p=new B(10,20,30);
p->Display();
delete p;
return 0;
}