1.打开终端 ，可以使用 Ctrl+Alt+T 快捷键直接打开；
2.在终端里输入 sudo gedit /etc/apt/sources.list 输入用户密码即可打开sources.list文档；
3.在打开的文档中删掉所有默认内容，添加 网易163 和 开源中国 oschina的更新源；
4.完成后保存，可直接用 Ctrl+S快捷键 完成。
附更新源内容：
#网易源（速度很快）
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 restricted
#OSCHINA
deb http://mirrors.oschina.net/ubuntu/ raring main restricted universe multiverse
deb http://mirrors.oschina.net/ubuntu/ raring-security main restricted universe multiverse
deb http://mirrors.oschina.net/ubuntu/ raring-updates main restricted universe multiverse
deb http://mirrors.oschina.net/ubuntu/ raring-proposed main restricted universe multiverse
deb http://mirrors.oschina.net/ubuntu/ raring-backports main restricted universe multiverse
deb-src http://mirrors.oschina.net/ubuntu/ raring main restricted universe multiverse
deb-src http://mirrors.oschina.net/ubuntu/ raring-security main restricted universe multiverse
deb-src http://mirrors.oschina.net/ubuntu/ raring-updates main restricted universe multiverse
deb-src http://mirrors.oschina.net/ubuntu/ raring-proposed main restricted universe multiverse
deb-src http://mirrors.oschina.net/ubuntu/ raring-backports main restricted universe multiverse

完成后即可在终端中输入 sudo apt-get update,此后即可设置中文界面，输入法等。

好帖

meiyong!

馃憤馃憤馃憤馃憤馃憤馃憤灏卞啀鎵捐繖涓?憿锛岃阿璋㈠お璋㈣阿

没用啊大神，求指点