我不小心跑了
sudo do-release-upgrade -d
并停止了它。但似乎它已将我的 Ubuntu 13.10 源更改为 14.04，如果我更新系统，它将自动升级。
我怎样才能将其恢复到以前的来源？
编辑：
我发现这些没有被选中：
于是我按照图片重新检查了一下。但我不确定一切是否和以前一样。
$ cat /etc/apt/sources.list
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
# deb http://archive.ubuntu.com/ubuntu saucy main restricted universe
## Major bug fix updates produced after the final release of the
## distribution.
# deb http://archive.ubuntu.com/ubuntu saucy-updates main restricted universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
# deb http://archive.ubuntu.com/ubuntu saucy multiverse
# deb http://archive.ubuntu.com/ubuntu saucy-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://archive.ubuntu.com/ubuntu saucy-backports main restricted multiverse universe
# deb http://archive.ubuntu.com/ubuntu saucy-security main restricted universe
# deb http://archive.ubuntu.com/ubuntu saucy-security multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu saucy partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://archive.ubuntu.com/ubuntu saucy main universe multiverse
deb http://security.ubuntu.com/ubuntu/ saucy-security multiverse main universe
deb http://archive.ubuntu.com/ubuntu saucy-updates multiverse main universe
和：
ponyo@ponyo-pc:~$ lsb_release -a
LSB Version: core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:core-3.1-ia32:core-3.1-noarch:core-3.2-ia32:core-3.2-noarch:core-4.0-ia32:core-4.0-noarch:core-4.1-ia32:core-4.1-noarch:security-4.0-ia32:security-4.0-noarch:security-4.1-ia32:security-4.1-noarch
Distributor ID: Ubuntu
Description: Ubuntu 13.10
Release: 13.10
Codename: saucy