cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu precise main universe restricted multiverse
deb-src http://archive.ubuntu.com/ubuntu precise universe main multiverse restricted

deb http://security.ubuntu.com/ubuntu/ precise-security universe main multiverse restricted
deb http://archive.ubuntu.com/ubuntu precise-updates universe main multiverse restricted
deb http://archive.ubuntu.com/ubuntu precise-backports universe main multiverse restricted

deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

# deb http://extras.ubuntu.com/ubuntu precise main
deb http://archive.canonical.com/ trusty partner
# deb-src http://archive.canonical.com/ trusty partner
# deb-src http://extras.ubuntu.com/ubuntu precise main