sudo mv/etc/apt/sources.list/etc/apt/sources.list.bak
sudo vi /etc/apt/sources.list
#中科大源
deb https://mirrors.ustc.edu.cn/Ubuntu/bionicmainrestricteduniversemultiverse
de B-src https://mirrors.ustc.edu.cn/Ubuntu/bionicmainrestricteduniversemultiverse
deb https://mirrors.ustc.edu.cn/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
de B-src https://mirrors.ustc.edu.cn/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
deb https://mirrors.ustc.edu.cn/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
de B-src https://mirrors.ustc.edu.cn/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
deb https://mirrors.ustc.edu.cn/Ubuntu/bionic-securitymainrestricteduniversemultiverse
de B-src https://mirrors.ustc.edu.cn/Ubuntu/bionic-securitymainrestricteduniversemultiverse
deb https://mirrors.ustc.edu.cn/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
#蚂蚁资源
deb http://mirrors.a liyun.com/Ubuntu/bionicmainrestricteduniversemultiverse
deb http://mirrors.a liyun.com/Ubuntu/bionic-securitymainrestricteduniversemultiverse
deb http://mirrors.a liyun.com/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
deb http://mirrors.a liyun.com/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
deb http://mirrors.a liyun.com/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
de B-src http://mirrors.a liyun.com/Ubuntu/bionicmainrestricteduniversemultiverse
de B-src http://mirrors.a liyun.com/Ubuntu/bionic-securitymainrestricteduniversemultiverse
de B-src http://mirrors.a liyun.com/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
de B-src http://mirrors.a liyun.com/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
de B-src http://mirrors.a liyun.com/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
##163源
deb http://mirrors.163.com/Ubuntu/bionicmainrestricteduniversemultiverse
deb http://mirrors.163.com/Ubuntu/bionic-securitymainrestricteduniversemultiverse
deb http://mirrors.163.com/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
deb http://mirrors.163.com/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
deb http://mirrors.163.com/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
de B-src http://mirrors.163.com/Ubuntu/bionicmainrestricteduniversemultiverse
de B-src http://mirrors.163.com/Ubuntu/bionic-securitymainrestricteduniversemultiverse
de B-src http://mirrors.163.com/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
de B-src http://mirrors.163.com/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
de B-src http://mirrors.163.com/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
#清华源
deb https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionicmainrestricteduniversemultiverse
de B-src https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionicmainrestricteduniversemultiverse
deb https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
de B-src https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-updatesmainrestricteduniversemultiverse
deb https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
de B-src https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-backportsmainrestricteduniversemultiverse
deb https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-securitymainrestricteduniversemultiverse
de B-src https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-securitymainrestricteduniversemultiverse
deb https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
de B-src https://mirrors.tuna.Tsinghua.edu.cn/Ubuntu/bionic-proposedmainrestricteduniversemultiverse
sudo apt-get update
sudo apt-get upgrade