private static void Main(string[] args)
{
Student s3 = new Student("王五", null);
Student s1 = new Student("张三", s3);
Student s2 = new Student("李四", s1);
Book b1 = new Book("赵六");
s2.CheckBook(b1);
Console.ReadLine();
}
public void CheckBook(Book book)
{
if (_name == book.Name)
{
Console.WriteLine("{0}：这是我的作业本，我收下了", _name);
}
else
{
if (_nextStudent != null)
{
Console.WriteLine("{0}：这不是我的作业本，我传给下一位同学了", _name);
_nextStudent.CheckBook(book);
}
else
{
Console.WriteLine("{0}：这不是我的作业本，但是后面没人了，作业本没人要了", _name);
}
}
}