如何修复“重复的sources.list条目”警告？

Question

每次我尝试进行一些更新 ( sudo apt-get update) 时，它都会说：

Reading package lists ... ready
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ need /partner amd64 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-amd64_Packages)
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ need /partner i386 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-i386_Packages)
W: You have to run apt-get update to correct these problems

来源列表：http : //paste.ubuntu.com/1180190/

ls /etc/apt/sources.list.d/ 按照要求：

milton@milton-HuronRiver-Platform:~$ ls /etc/apt/sources.list.d/
emesene-team-emesene-stable-precise.list
precise-partner.list
precise-partner.list.save
upubuntu-com-chat-precise.list
upubuntu-com-chat-precise.list.save