换源

    解决Ubuntu更新慢问题：换源

   在终端里输入 sudo gedit /etc/apt/sources.list

你就能看到源列表了，把你看到的都删除然后粘贴上适合你的源

复制粘贴以下内容：

#Ubuntu.cn99.com更新服务器（推荐电信用户使用）：

deb http://ubuntu.cn99.com/ubuntu/ intrepid main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ intrepid-security main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ intrepid-updates main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ intrepid-proposed main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ intrepid-backports main restricted universe multiverse
deb-src http://ubuntu.cn99.com/ubuntu/ intrepid main restricted universe multiverse
deb-src http://ubuntu.cn99.com/ubuntu/ intrepid-security main restricted universe multiverse
deb-src http://ubuntu.cn99.com/ubuntu/ intrepid-updates main restricted universe multiverse
deb-src http://ubuntu.cn99.com/ubuntu/ intrepid-proposed main restricted universe multiverse
deb-src http://ubuntu.cn99.com/ubuntu/ intrepid-backports main restricted universe multiverse

#上海市上海交通大学更新服务器（教育网，推荐校园网和网通用户使用）：

deb http://ftp.sjtu.edu.cn/ubuntu/ intrepid main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ intrepid-backports main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ intrepid-proposed main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ intrepid-security main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ intrepid-updates main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ intrepid main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ intrepid-backports main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ intrepid-proposed main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ intrepid-security main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ intrepid-updates main multiverse restricted universe

保存退出

在终端输入   sudo apt-get update   更新列表

这样，换源完成