Ubuntu Update (upgrade source in China)

Open the terminal (Oh, you don't have to say that, everyone on Earth knows)
1) input: sudo CP/etc/APT/sources. LIST/etc/APT/sources. List. Backup // This is to save the current source list
2) Enter sudo gedit/etc/APT/sources. List // to edit the source list.

In this case, the open source list will be created using gedit. After all the options are selected, copy the following contents to overwrite all the original content:
Bytes -----------------------------------------------------------------------------------------------------------
Deb http://ubuntu.cn99.com/ubuntu/ feisty main restricted universe multiverse
Deb http://ubuntu.cn99.com/ubuntu/ feisty-security main restricted universe multiverse
Deb http://ubuntu.cn99.com/ubuntu/ feisty-Updates main restricted universe multiverse
Deb http://ubuntu.cn99.com/ubuntu/ feisty-proposed main restricted universe multiverse
Deb http://ubuntu.cn99.com/ubuntu/ feisty-backports main restricted universe multiverse
The Deb-Src http://ubuntu.cn99.com/ubuntu/ feisty main restricted universe multiverse
Deb-Src http://ubuntu.cn99.com/ubuntu/ feisty-security main restricted universe multiverse
Deb-Src http://ubuntu.cn99.com/ubuntu/ feisty-Updates main restricted universe multiverse
Deb-Src http://ubuntu.cn99.com/ubuntu/ feisty-proposed main restricted universe multiverse
Deb-Src http://ubuntu.cn99.com/ubuntu/ feisty-backports main restricted universe multiverse
Bytes --------------------------------------------------------------------------------------------------------------

after this step is completed, save the edited source and Close sources. list, and then return to the terminal and enter the following command:
3 .) input: sudo apt-Get update
4 .) input: sudo apt-Get dist-upgrade
Haha, as long as there is no error above, the source has been successfully replaced with the cn99 source, now you have to configure the Chinese environment. Pai_^