sudo sed -i 's@http://apt.pop-os.org/@https://mirror.sjtu.edu.cn/pop-os/@g' /etc/apt/sources.list.d/pop-os-apps.sources sudo sed -i 's@http://apt.pop-os.org/@https://mirror.sjtu.edu.cn/pop-os/@g' /etc/apt/sources.list.d/pop-os-release.sources sudo sed -i 's@http://apt.pop-os.org/@https://mirror.sjtu.edu.cn/@g' /etc/apt/sources.list.d/system.sources