1、备份原文件
cd /etc/apt/sources.list.d/
cp ubuntu.sources ubuntu.sources.bak
        2、修改镜像源
Types: deb
URIs:   https://mirrors.aliyun.com/ubuntu/
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Types: deb
URIs:   https://mirrors.aliyun.com/ubuntu/
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
修改镜像源为国内镜像源
镜像源	地址
阿里云	https://mirrors.aliyun.com/ubuntu/
清华大学	https://mirrors.tuna.tsinghua.edu.cn/ubuntu/
华为云	https://mirrors.huaweicloud.com/repository/ubuntu/
        3、更新镜像源
apt update && sudo apt upgrade -y