Ubuntu快速下載換源網址
下載網址：
http://mirrors.aliyun.com/ubuntu-releases/14.04/
http://mirrors.aliyun.com/ubuntu-releases/16.04/
http://mirrors.aliyun.com/ubuntu-releases/18.04/
換源：
sudo cp /etc/apt/sources.list /etc/apt/sources_init.list
sudo gedit /etc/apt/sources.list
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
更新：
sudo apt-get update
sudo apt-get upgrade
Windows操作系統下可直接轉到對應網址下載：
官網下載速遞20KB,換源測試下載速度4MB…