使用阿里或者其他国内镜像源包含了一些自带源没有的软件包，在速度上也相对快一些
- 使用vim或者gedit命令编辑/etc/apt/sources.list文件
#使用vim编辑
$sudo vim /etc/apt/sources.list
#使用gedit编辑
$sudo gedit /etc/apt/sources.list
- 在文档开始位置输入以下代码
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
编辑sources.list
保存退出
使用命令更新缓存
$sudo apt-get update
$sudo apt-get upgrade
