这是命令#apt-get update 的输出。我也无法使用更新管理器更新任何软件包。问题是什么？
Ign http://mirrors.dotsrc.org precise-getdeb InRelease
Ign http://ppa.launchpad.net precise InRelease
Ign http://ppa.launchpad.net precise InRelease
Ign http://ppa.launchpad.net precise InRelease
Ign http://ppa.launchpad.net precise InRelease
Get:1 http://www.remastersys.com precise InRelease [2,069 B]
Get:2 http://mirrors.dotsrc.org precise-getdeb Release.gpg [836 B]
Ign http://archive.ubuntu.com precise InRelease
Ign http://archive.ubuntu.com precise-updates InRelease
Ign http://archive.ubuntu.com precise-backports InRelease
Ign http://archive.ubuntu.com precise-security InRelease
Get:3 http://ppa.launchpad.net precise Release.gpg [316 B]
Hit http://ppa.launchpad.net precise Release.gpg
Hit http://mirrors.dotsrc.org precise-getdeb Release
Hit http://www.remastersys.com precise/main i386 Packages
Hit http://ppa.launchpad.net precise Release.gpg
Get:4 http://archive.ubuntu.com precise Release.gpg [198 B] …