两个星号

#include<stdio.h>
class CPicture
{
public:
CPicture()
{
    printf("PIC::Create\n");
}
virtual ~CPicture()
{
    printf("PIC::Destory\n");
}
public:
    void Open()
    {
    printf("PIC::Open\n");
    virtual void convert()
    {
        open();
        printf("PIC::Convert\n");
    }
    virtual void Close()=0;
    };
    class CBMP:public CPiture
    {
    public:
    CBMP()
    {
    printf("BMP::Create\n");
    }
    ~CBMP()
    printf("BMP::Destroy\n");
    }
    public:
        void open()
        {
        printf("bmp::Open\n");
        }
        void Close()
        {
        Convert();
        printf("BMP::close\n");
        }
};
int main(int argc,char**argv)
{
CPiture *pPIC=new CBMP;
pPIC->Close();
delete pPIC;
return 0;
}


谁能说下  哪错了  并说下char**argv 是什么意思