如果是高手，请翻到页面最下方，更换更新源的总结，直接操作即可
可能会优点啰嗦，但是认真看，一定能解决问题~~希望对大家有帮助~
最近在熟悉linux环境，自己安装了一个ubuntu虚拟机。 很多朋友问装了ubuntu怎么改成中文版，装完系统后可能没有中文包，自动联网下载又连不上外国的服务器。所以在这里，我把自己更换软件更新源的方法写出来分享一下~
更新源是什么呢？？ 在ubuntu系统中，有一个文件，里面放着更新源信息，当我们下载软件的时候，都会去文件里找去哪个服务器下载。但是系统是人家外国人的，更新源默认都是外国服务器，我们下载软件自然很吃力。
解决办法：我们把更新源改成中国的服务器吧~~~
下面我会一步一步操作一下更改更新源：
1 跳到更新源文件所在的目录下，终端执行：
cd /etc/apt/
此时，我们可以在当前目录看一下里面的文件，终端执行: ls 我们会看到当前目录下所有文件，不出意外 会有一个sources.list文件，这个文件里面写的就是更新源。我们接下来都是对它进行操作
2 将原来的更新源备份一下，注意要用管理员权限进行操作，终端执行：
sudo cp sources.list copy_sources.list
此时，当前目录下会多一个copy_sources.list的文件，是我们自己的备份，万一我们把更新源改坏了，还可以恢复回来
3 更换更新源
我们可以在百度上搜索“ubuntu xxxx版本 更新源”，类似这样的关键字，就能搜到。
我们挑选一个自己喜欢的更新源，将上面的源码复制一下，粘贴到sources.list源文件里面覆盖原来的内容保存，这样就改掉了更新源。但是往往需要我们用管理员权限，具体操作：终端中执行：
sudo gedit sources.list
然后复制更新源代码，更换sources.list文件里的代码，保存，退出。
ok了！！到了这里基本完成了
ubuntu16.04版本的更新源：
东北大学
deb-src http://mirror.neu.edu.cn/ubuntu/ xenial main restricted #Added by software-properties
deb http://mirror.neu.edu.cn/ubuntu/ xenial main restricted
deb-src http://mirror.neu.edu.cn/ubuntu/ xenial restricted multiverse universe #Added by software-properties
deb http://mirror.neu.edu.cn/ubuntu/ xenial-updates main restricted
deb-src http://mirror.neu.edu.cn/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties
deb http://mirror.neu.edu.cn/ubuntu/ xenial universe
deb http://mirror.neu.edu.cn/ubuntu/ xenial-updates universe
deb http://mirror.neu.edu.cn/ubuntu/ xenial multiverse
deb http://mirror.neu.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirror.neu.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirror.neu.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://mirror.neu.edu.cn/ubuntu/ xenial-security main restricted
deb-src http://mirror.neu.edu.cn/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties
deb http://mirror.neu.edu.cn/ubuntu/ xenial-security universe
deb http://mirror.neu.edu.cn/ubuntu/ xenial-security multiverse
清华大学
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse
阿里云
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse
-------------------------------------------------------
ubuntu1 18 版本的更新源：
阿里的
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
中科大的
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
163网易的
deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
清华大学的
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
4 检查一下是否能成功下载软件，终端执行
sudo apt-get update
等待进度完成，我们的ubuntu就能够从国内的服务器下载软件了~~~~
~总结一下(干货！省略很多步骤，菜鸟不要直接参考)：
1 打开更新源文件并编辑：终端： sudo gedit /etc/apt/sources.list 或者 sudo vim /etc/apt/sources.list
2 搜所适合自己的更新源服务器代码，也可参考上面我分享给大家的，把代码复制，粘贴替换sources.list文件里的代码，保存退出
3 终端：sudo apt-get update
结束！