换成阿里的源
1、打开source文件，sudo gedit /etc/apt/source.list，将内容替换为：
- # 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
2.更新：sudo apt-get update
