sudo apt-get update每当我在终端中输入时，我都会收到以下错误：
Ign http://se.archive.ubuntu.com saucy/main Translation-en_US
Ign http://se.archive.ubuntu.com saucy/multiverse Translation-en_US
Ign http://se.archive.ubuntu.com saucy/restricted Translation-en_US
Ign http://se.archive.ubuntu.com saucy/universe Translation-en_US
Ign http://se.archive.ubuntu.com saucy-updates/main Translation-en_US
Ign http://se.archive.ubuntu.com saucy-updates/multiverse Translation-en_US
Ign http://se.archive.ubuntu.com saucy-updates/restricted Translation-en_US
Get:11 http://security.ubuntu.com saucy-security/main i386 Packages [63,4 kB]
Ign http://se.archive.ubuntu.com saucy-updates/universe Translation-en_US
Ign http://se.archive.ubuntu.com saucy-backports/main Translation-en_US
Ign http://se.archive.ubuntu.com saucy-backports/multiverse Translation-en_US
Ign http://se.archive.ubuntu.com saucy-backports/restricted Translation-en_US
Ign http://se.archive.ubuntu.com saucy-backports/universe Translation-en_US
Get:12 http://security.ubuntu.com saucy-security/restricted i386 Packages [14 B]
Get:13 http://security.ubuntu.com saucy-security/universe i386 Packages [24,4 kB]
Get:14 http://security.ubuntu.com saucy-security/multiverse i386 Packages [1 388 B]
Err http://ppa.launchpad.net saucy/main amd64 Packages
404 Not Found
Err http://ppa.launchpad.net saucy/main i386 Packages
404 Not Found
Ign http://ppa.launchpad.net saucy/main Translation-en_US
Ign http://ppa.launchpad.net saucy/main Translation-en
Err http://ppa.launchpad.net saucy/main amd64 Packages
404 Not Found
Hit http://security.ubuntu.com saucy-security/main Translation-en
Err http://ppa.launchpad.net saucy/main i386 Packages
404 Not Found
Ign http://ppa.launchpad.net saucy/main Translation-en_US
Ign http://ppa.launchpad.net saucy/main Translation-en
Err http://ppa.launchpad.net saucy/main amd64 Packages
404 Not Found
Err http://ppa.launchpad.net saucy/main i386 Packages
404 Not Found
Ign http://ppa.launchpad.net saucy/main Translation-en_US
Hit http://security.ubuntu.com saucy-security/multiverse Translation-en
Ign http://ppa.launchpad.net saucy/main Translation-en
Hit http://security.ubuntu.com saucy-security/restricted Translation-en
Hit http://security.ubuntu.com saucy-security/universe Translation-en
Ign http://security.ubuntu.com saucy-security/main Translation-en_US
Ign http://security.ubuntu.com saucy-security/multiverse Translation-en_US
Ign http://security.ubuntu.com saucy-security/restricted Translation-en_US
Ign http://security.ubuntu.com saucy-security/universe Translation-en_US
Fetched 259 kB in 5s (48,9 kB/s)
W: Failed to fetch cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1)/dists/saucy/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1)/dists/saucy/restricted/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1)/dists/saucy/main/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1)/dists/saucy/restricted/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch http://ppa.launchpad.net/revl/codimension/ubuntu/dists/saucy/main/binary-amd64/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/revl/codimension/ubuntu/dists/saucy/main/binary-i386/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/tor/ubuntu/dists/saucy/main/binary-amd64/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/tor/ubuntu/dists/saucy/main/binary-i386/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/tor64/ubuntu/dists/saucy/main/binary-amd64/Packages 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/tor64/ubuntu/dists/saucy/main/binary-i386/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
这是什么意思？我非常感谢大家的帮助！:)
我运行的是 Ubuntu 13.10，我最近安装了它，总体上对它很满意。
答案1
这是因为源 tor 64 尚未更新，尚未准备好用于 saucy get，codimension 也是如此，对于 cdrom，只需在软件源上取消选中 cdrom，然后您可以取消选中其他源，直到它准备好用于 soucy。