ubuntu resolves a replacement source failure issue

Open a window with the graphical interface command
In Terminal input Gksudo nautilus
Open a graphics window (note that files in any directory under this graphics window can be deleted)


/ect/apt
Delete the following sources.list and backup files sources.list.save
And then go to the next level directory.
/ect/apt/SOURCES.LIST.D
Remove all of the following files
It's going to be a normal situation here.
(if not, go to the following directory and delete all the files.)
/var/lib/apt/lists)
and then into
Update Manager
Select the Chinese server, plus the above relevant options point when closed prompt reload on it.

ubuntu resolves a replacement source failure issue