自己写一个，免得每次安装都去搜索
#gedit /etc/apt/sources.list
deb http://Ubuntu.cn99.com/ubuntu/ lucid main universe restricted multiverse
deb-src http://Ubuntu.cn99.com/ubuntu/ lucid main universe restricted multiverse
deb http://Ubuntu.cn99.com/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://Ubuntu.cn99.com/ubuntu/ lucid-security universe main multiverse restricted
deb http://Ubuntu.cn99.com/ubuntu/ lucid-updates universe main multiverse restricted
deb http://Ubuntu.cn99.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://Ubuntu.cn99.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://Ubuntu.cn99.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://Ubuntu.cn99.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://Ubuntu.cn99.com/ubuntu/ lucid-updates universe main multiverse restricte