student@student-desktop:~$ sudo apt-get update
Err http://bd.archive.ubuntu.com karmic Release.gpg
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic/main Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic/restricted Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic/universe Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic/multiverse Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic-updates Release.gpg
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic-updates/main Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic-updates/restricted Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic-updates/universe Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://bd.archive.ubuntu.com karmic-updates/multiverse Translation-en_US
Could not resolve 'bd.archive.ubuntu.com'
Err http://archive.canonical.com karmic Release.gpg
Could not resolve 'archive.canonical.com'
Err http://archive.canonical.com karmic/partner Translation-en_US
Could not resolve 'archive.canonical.com'
Err http://security.ubuntu.com karmic-security Release.gpg
Could not resolve 'security.ubuntu.com'
Err http://security.ubuntu.com karmic-security/main Translation-en_US
Could not resolve 'security.ubuntu.com'
Err http://security.ubuntu.com karmic-security/restricted Translation-en_US
Could not resolve 'security.ubuntu.com'
Err http://security.ubuntu.com karmic-security/universe Translation-en_US
Could not resolve 'security.ubuntu.com'
Err http://security.ubuntu.com karmic-security/multiverse Translation-en_US
Could not resolve 'security.ubuntu.com'
Reading package lists... Done
W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/...ic/Release.gpg Could not resolve 'bd.archive.ubuntu.com'

W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/...tion-en_US.bz2 Could not resolve 'bd.archive.ubuntu.com'

W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/...tion-en_US.bz2 Could not resolve 'bd.archive.ubuntu.com'

W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/...tion-en_US.bz2 Could not resolve 'bd.archive.ubuntu.com'

student@student-desktop:~$
hi there, when I wanted to update my repository list in ubuntu 9.10 of our Lab than the terminal showing those error message!! please help me how can I update my repository list. thanks in advance.