c++的问题，找错！

#include<iostream.h>
class BOOK
{public:
char Bname;
char Bnum;
char author;
BOOK(char a,char b,char c)
{Bname=a; Bnum=b; author=c;}
void display1();
};
void BOOK::display1()
{
cout<<"书名："<<Bname<<endl;
cout<<"书号："<<Bnum<<endl;
cout<<"作者名："<<author<<endl;
}

class Reader : public BOOK
{
char Rname;
char Rnum;
int booknum;

public:
Reader(char d,char e,int f)//有错！
{Rname=d; Rnum=e; booknum=f;}
void display2();
};
void Reader::display2()
{
cout<<"姓名："<<Rname<<endl;
cout<<"卡号："<<Rnum<<endl;
cout<<"已借书数："<<booknum<<endl;
cout<<"已借书情况："<<endl;
display1();
}

#include<iostream.h>
class BOOK
{public:
char Bname;
char Bnum;
char author;
BOOK(char a,char b,char c)
{Bname=a; Bnum=b; author=c;}
void display1();
};
void BOOK::display1()
{
cout<<"书名："<<Bname<<endl;
cout<<"书号："<<Bnum<<endl;
cout<<"作者名："<<author<<endl;
}

class Reader : public BOOK
{
char Rname;
char Rnum;
int booknum;

public:
Reader(char a,char b,char c,char d,char e,int f):BOOK(a,b,c)//构造函数的问题，你没有关于书的信息你怎么初始化啊？
{Rname=d; Rnum=e; booknum=f;}
void display2();
};
void Reader::display2()
{
cout<<"姓名："<<Rname<<endl;
cout<<"卡号："<<Rnum<<endl;
cout<<"已借书数："<<booknum<<endl;
cout<<"已借书情况："<<endl;