在sources.list里面添加了新的源，旧的需要删除吗？

添加了http://www.ubuntu.org.cn的三个horay的deb包源
deb http://archive.ubuntu.org.cn/ubuntu hoary main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu hoary-security main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu hoary-updates main restricted universe multiverse

需不需要把前面的这些删除掉？
deb cdrom:[Ubuntu 5.04 _Hoary Hedgehog_ - Release i386 (20050407)]/ hoary main restricted


deb http://cn.archive.ubuntu.com/ubuntu hoary main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu hoary main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://cn.archive.ubuntu.com/ubuntu hoary-updates main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu hoary-updates main restricted

## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
# deb http://cn.archive.ubuntu.com/ubuntu hoary universe
# deb-src http://cn.archive.ubuntu.com/ubuntu hoary universe

deb http://security.ubuntu.com/ubuntu hoary-security main restricted

# deb http://security.ubuntu.com/ubuntu hoary-security universe
# deb-src http://security.ubuntu.com/ubuntu hoary-security universe

把它们注释掉就是

第一行也注释掉吗？

如果是新的话，系统会自动安装新版本，不必把旧的注释掉，不过这样，数据库会稍大一些~~

注释掉