答案1
这是标准/etc/apt/sources.list
文件:
deb http://archive.ubuntu.com/ubuntu/ focal main restricted
deb http://security.ubuntu.com/ubuntu/ focal-security main restricted
deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted
备份当前文件后复制粘贴,source.list
然后运行sudo apt update
。另外,当你想添加 PPA 时,请注意 ubuntu 20.04 的代号是焦点不是埃科安即19.10。