C++代码编译，哪错了？

//student.h
#include <iostream>
using namespace std;
class student//因为存在纯虚函数study，student 类自动变成了抽象类
{ public:
student( char *n,int a,int h,int w);
student(); void set(char *n,int a,int h,int w);
char * sname();
int sage();
int sheight();
int sweight();
virtual void study()=0;//声明study 为纯虚函数
protected:
char name[10];
int age;
int height;
int weight;
};
char * student::sname()
{ return name;
} int student::sage()
{ return age;
} int student::sheight()
{ return height;
} int student::sweight()
{ return weight;
} void student::set(char *n,int a,int h,int w)
{ int i;
for (i=0;n[i]!='\0';i++)
{
name[i]=n[i];
}
name[i]='\0';
age= a;
height=h;
weight=w;
return;
}
student::student(char *n,int a,int h,int w)