求各位C#牛人！！
请各位大神、牛人给我一些指点，我是初学者，能不能把下面这段windows窗口程序的代码解释一下，最好吧么一句的注释解释详细一点！谢谢



using System;

namespace MyFirstProgram
{
  public class Person
  {
  string name;
  Char sex;
   
  public Person(){}
  public Person(string s,char x)
  {
  name=s;
  sex=x;
  }
  public void printinfo ()
  {
  Console.Write(name+'('+sex+')');
  }

  }
  public class Student:Person
  {  
  int studentID;
  int credit;
  public Student(){}
  public Student(int sID,int ct,string s,char x):base(s,x) 
  {
  studentID=sID;
  credit = ct;
  }
   
  void graduate() 
  { 
  if (credit>200) 
  Console.WriteLine("恭喜，你可以毕业了！");
  }
  public class Teacher:Person
  {
  int staffID;
  int course;
  public Teacher(){}
  public Teacher(string s,Char x,int sID):base(s,x) 
  {
  staffID=sID;
  }
  void coursenumber(int cn)
  {
  course=cn;
  }
   
  }

  static void Main(string[] args)
  {
  Person a = new Person("aaa",'d');
  Student Wang = new Student(12200035,120,"王贵阳",'男');
  Student Chen = new Student(12010018,130,"陈小娅",'女'); 
  Teacher Li = new Teacher("李海", '男',08100082); //, 
  if (Wang.credit > 100)
  {
  Wang.printinfo();
  Console.Write("你的老师是");
  Li.printinfo();
  Console.WriteLine();
  }
  if (Chen.credit > 100)
  {
  Chen.printinfo();
  Console.Write("你的老师是");
  Li.printinfo();
  Console.WriteLine();
  }
  }
  }
}



------解决方案--------------------

C# code

using System;

namespace MyFirstProgram
{
    //定义Person类
  public class Person
  {
  string name;
  Char sex;
    //无参数构造
  public Person(){}
  //带参数构造
  public Person(string s,char x)
  {
  name=s;
  sex=x;
  }
  public void printinfo ()
  {
  Console.Write(name+'('+sex+')');
  }

  }
  //类Student继承自Person
  public class Student:Person
  {   
  int studentID;
  int credit;
  //无参数构造
  public Student(){}
  //带参数构造，base调用父类带参数构造
  public Student(int sID,int ct,string s,char x):base(s,x)  
  {
  studentID=sID;
  credit = ct;
  }
    
  void graduate()  
  {  
  if (credit>200)  
  Console.WriteLine("恭喜，你可以毕业了！");
  }
  //同student类
  public class Teacher:Person
  {
  int staffID;
  int course;
  public Teacher(){}
  public Teacher(string s,Char x,int sID):base(s,x)  
  {
  staffID=sID;
  }
  void coursenumber(int cn)
  {
  course=cn;
  }
    
  }

------解决方案--------------------
using System;--命名空间

namespace MyFirstProgram
{
  public class Person
  {
  string name;--声明变量（姓名，字符串型的）
  Char sex;--声明变量（性别，Char型）