当我尝试通过 Ubuntu 软件中心安装 Audacity 时，屏幕最初显示：
Available from the "universe" source
然后我点击使用此来源按钮，系统会要求输入密码。但是，在我输入登录密码后，系统显示进度1后来出现以下错误：
Failed to download repository information
Check your Internet connection
我也尝试安装 VLC Player，但结果类似。有人能在这方面帮助我吗，因为我对 Ubuntu 平台还很陌生？
答案1
好的，您可以这样做。我们将尝试通过命令行安装这两个程序，因为这样，我们将能够看到有关具体情况的更多信息。在开始之前，请确保您已连接到互联网。然后，请按照以下步骤操作：
步骤1
点击Ctrl+ Alt+ T。这将打开一个窗口，称为终端。在此窗口中，首先输入以下内容：
sudo apt-get update
当系统要求输入密码时，输入您的密码。然后会开始显示很多行。这只是更新您的“源”，这样当您安装程序时，您就可以无缝地完成。
第2步
接下来输入以下内容：
sudo apt-get install audacity
你应该得到类似下面的结果：
alaa@aa-UBUNTU:~$ sudo apt-get install audacity
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
audacity-data libflac++6 libid3tag0 libportsmf0 libsbsms10 libsoundtouch0 libsoxr0 libvamp-hostsdk3
Suggested packages:
ladspa-plugin
The following NEW packages will be installed:
audacity audacity-data libflac++6 libid3tag0 libportsmf0 libsbsms10 libsoundtouch0 libsoxr0 libvamp-hostsdk3
0 upgraded, 9 newly installed, 0 to remove and 0 not upgraded.
Need to get 5,936 kB of archives.
After this operation, 16.8 MB of additional disk space will be used.
Do you want to continue [Y/n]?
如果确实收到此信息，只需键入y并按回车键。这将开始下载并安装 Audacity。完成后，只需在您的程序中搜索 Audacity，您就会在那里找到它。如果您没有收到与上述类似的信息，或者在运行sudo apt-get update我之前给您的命令时发生了某些事情，请编辑您的消息以包含错误。
如果一切顺利，并且 Audacity 安装正确，您可以对 VLC 执行相同的操作；您可以通过键入以下内容来安装它：
sudo apt-get install vlc
编辑
从评论来看，您的 sources.list 文件已损坏。请按照以下说明操作：
在终端中输入以下命令：
gksu gedit /etc/apt/sources.list
出现提示时输入您的密码（新密码）。这将打开一个文本编辑器，如记事本，里面有一些文本。删除里面的所有文本，然后将以下所有内容复制到其中：
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ raring main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ raring-updates main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring-updates main restricted
## 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.
deb http://gb.archive.ubuntu.com/ubuntu/ raring universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring universe
deb http://gb.archive.ubuntu.com/ubuntu/ raring-updates universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring-updates universe
## 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://gb.archive.ubuntu.com/ubuntu/ raring multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ raring-updates multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring-updates multiverse
## Uncomment the following two lines to add software from the 'backports'
## repository.
## 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://gb.archive.ubuntu.com/ubuntu/ raring-backports main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ raring-backports main restricted universe 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 raring partner
deb-src http://archive.canonical.com/ubuntu raring partner
deb http://security.ubuntu.com/ubuntu raring-security main restricted
deb-src http://security.ubuntu.com/ubuntu raring-security main restricted
deb http://security.ubuntu.com/ubuntu raring-security universe
deb-src http://security.ubuntu.com/ubuntu raring-security universe
deb http://security.ubuntu.com/ubuntu raring-security multiverse
deb-src http://security.ubuntu.com/ubuntu raring-security multiverse
按Ctrl+S保存文件，然后关闭此窗口。这将带您返回终端。现在，按照我原始答案中的步骤操作（步骤 1 和步骤 2）。