2.                     
                            
                
                    
                
                    
        OCW makes the materials used in the teaching of MIT's subjects available on the Web.
         
         
         
        Learn more about how to use OpenCourseWare. Click to get started.
                            
               
           
           
                        
           
          1. 
http://www.nhde20.cn |

http://m.nhde20.cn |

http://wap.nhde20.cn |

http://3g.nhde20.cn |

http://4g.nhde20.cn |

http://5g.nhde20.cn |

http://mobile.nhde20.cn |

http://vip.nhde20.cn |

http://ios.nhde20.cn |

http://anzhuo.nhde20.cn |

http://e.nhde20.cn |

http://d178.nhde20.cn |

http://37c9.nhde20.cn |

http://b45793.nhde20.cn/4b06.html |

http://b45793.nhde20.cn/3527a.html |

http://b45793.nhde20.cn/f.html |

 youtube18以上视频