一、编辑 /etc/apt/sources.list
替换至/etc/apt/sources.list文件中。
deb http://mirrors.tencentyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.tencentyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.tencentyun.com/ubuntu/ bionic-updates main restricted universe multiverse
#deb http://mirrors.tencentyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
#deb http://mirrors.tencentyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.tencentyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.tencentyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.tencentyun.com/ubuntu/ bionic-updates main restricted universe multiverse
#deb-src http://mirrors.tencentyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
#deb-src http://mirrors.tencentyun.com/ubuntu/ bionic-backports main restricted universe multiverse
三、刷新软件源信息：
sudo apt update
四、更新软件
sudo apt upgrade
