速度還行的更新源，儲存在這備用
先備份原來的更新原始檔：
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup
編輯更新源：
sudo gedit /etc/apt/sources.list
將裡面的全部內容替換為：
deb http://ubuntu.srt.cn/ubuntu/ lucid main universe restricted multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid main universe restricted multiverse
deb http://ubuntu.srt.cn/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-security universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ lucid-updates universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-updates universe main multiverse restricted
更新源資訊：
sudo apt-get update
如果要全面更新系統，請使用下面的命令：
sudo apt-get upgrade
From:http://www.cnblogs.com/heaad/archive/2010/05/02/1725860.html