## ubuntu20
```
deb http://mirrors.aliyun.com/ubuntu/ focal main restricted
deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted
deb http://mirrors.aliyun.com/ubuntu/ focal universe
deb http://mirrors.aliyun.com/ubuntu/ focal-updates universe
deb http://mirrors.aliyun.com/ubuntu/ focal multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted
deb http://mirrors.aliyun.com/ubuntu/ focal-security universe
deb http://mirrors.aliyun.com/ubuntu/ focal-security multiverse
```
