Cd/etc/aptcat sources.listsudo su rootsudo echo ' > Sources.listnano sources.list copy 163 software source Deb http://mirrors.163.com /ubuntu/precise main Universe restricted multiverse deb-src http://mirrors.163.com/ubuntu/precise main universe Restricted Multiverse deb http://mirrors.163.com/ubuntu/precise-security Universe main Multiverse restricted  DEB-SRC http://mirrors.163.com/ubuntu/precise-security Universe main Multiverse Restricted deb/HTTP Mirrors.163.com/ubuntu/precise-updates Universe main Multiverse Restricted deb http://mirrors.163.com/ubuntu/ Precise-proposed Universe main Multiverse restricted deb-src http://mirrors.163.com/ubuntu/precise-proposed Universe main Multiverse Restricted deb Http://mirrors.163.com/ubuntu/precise-backports universe main Multiverse RESTRICTED DEB-SRC Http://mirrors.163.com/ubuntu/precise-backports Universe main Multiverse restricted DEB-SRC Http://mirrors.163.com/ubuntu/precise-updates Universe Main mUltiverse restrictedctrl+o--Enter--ctrl+x--enter su ubuntu sudo apt-get updatesudo apt-get Upgrade
Done.
Ubuntu Modified 163 Software source