mv /etc/apt/sources.list /etc/apt/sources.list.back
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse" >>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse" >>/etc/apt/sources.list
apt update&&apt upgrade