执行更新数据(sudo apt-get update)提示:
Err https://mirrors.aliyun.com trusty Release.gpg
Could not resolve 'mirrors.aliyun.com'
Err https://mirrors.aliyun.com trusty-updates Release.gpg
Could not resolve 'mirrors.aliyun.com'
Err https://mirrors.aliyun.com trusty-backports Release.gpg
Could not resolve 'mirrors.aliyun.com'
Err https://mirrors.aliyun.com trusty-security Release.gpg
Could not resolve 'mirrors.aliyun.com'
Reading package lists... Done
W: Failed to fetch https://mirrors.aliyun.com/ubuntu/dists/trusty/InReleaseErr https://mi
