如國內網絡使用ubuntu 則會出現apt-get無法安裝更新的問題，這時大家需要切換到一些國內第三方更新源。
- 首先查看自己的ubuntu系統的codename，直接導致你更新的源是否對你的系統起效果，查看方法： lsb_release -a
我的系統顯示：Codename: bionic 確認阿里源支持
登陸以下網頁：http://mirrors.aliyun.com/ubuntu/dists/
該網頁顯示了阿里雲支持的ubuntu系統下各個Codename版本，確保自己的Codename在該網頁中存在（一般都會有的）備份系統源：
cd /etc/apt
sudo mv sources.list sources.list_bak添加新的源文件：sudo vi sources.list
並添加以下內容：注意，每一行的trusty應該用第一步查看得到的Codename來代替
deb http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe保存並且sudo apt-get update，更新成功
