如国内网络使用ubuntu 则会出现apt-get无法安装更新的问题，这时大家需要切换到一些国内第三方更新源。
- 首先查看自己的ubuntu系统的codename，直接导致你更新的源是否对你的系统起效果，查看方法： lsb_release -a
我的系统显示结果是：Codename: xenial - 确认阿里源支持
登陆以下网页：mirrors.aliyun.com/ubuntu/dist…
该网页显示了阿里云支持的ubuntu系统下各个Codename版本，确保自己的Codename在该网页中存在（一般都会有的） - 备份系统源：
cd /etc/apt
sudo mv sources.list sources.list_bak - 添加新的源文件：sudo vi sources.list
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb-src archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties
deb mirrors.aliyun.com/ubuntu/ xenial main restricted
deb-src mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties
deb mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
deb-src mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties
deb mirrors.aliyun.com/ubuntu/ xenial universe
deb mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb mirrors.aliyun.com/ubuntu/ xenial multiverse
deb mirrors.aliyun.com/ubuntu/ xenial-updates multiverse
deb mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties
deb archive.canonical.com/ubuntu xenial partner
deb-src archive.canonical.com/ubuntu xenial partner
deb mirrors.aliyun.com/ubuntu/ xenial-security main restricted
deb-src mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties
deb mirrors.aliyun.com/ubuntu/ xenial-security universe
deb mirrors.aliyun.com/ubuntu/ xenial-security multiverse - 保存并且sudo apt-get update，更新成功
