Ubuntu 11.04网易源（速度很快，推荐）
#Ubuntu 11.04网易源（速度很快，推荐）
deb http://mirrors.163.com/ubuntu/ natty main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ natty main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ natty-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-updates universe main multiverse restricted