安装的Ubuntu安装东西速度实在是不敢恭维QAQ，因为是国外的网址。
所以我们要换成国内的源，然后就可以尽情飞越了。
首先我们还是要先备份下：sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
接下来：sudo vim /etc/apt/sources.list
然后把里面的东西全删除，
我们来到
找到Ubuntu，把里面内容换成如下：
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src 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-backports main restricted universe multiverse然后
sudo apt-get update
sudo apt-get upgrade就OK了。
