I am not able to update and install anything in virtual box. It shows error
Err:1 https://download.sublimetext.com apt/stable/ InRelease
Could not resolve host: download.sublimetext.com
Err:2 http://ppa.launchpad.net/mozillateam/firefox-next/ubuntu xenial InRelease
Temporary failure resolving 'ppa.launchpad.net'
Err:3 http://us.archive.ubuntu.com/ubuntu xenial InRelease
Temporary failure resolving 'us.archive.ubuntu.com'
Err:4 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease
Temporary failure resolving 'ppa.launchpad.net'
Reading package lists... Done
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial/InRelease Temporary failure resolving 'us.archive.ubuntu.com'
W: Failed to fetch http://ppa.launchpad.net/mozillateam/firefox-next/ubuntu/dists/xenial/InRelease Temporary failure resolving 'ppa.launchpad.net'
W: Failed to fetch https://download.sublimetext.com/apt/stable/InRelease Could not resolve host: download.sublimetext.com
W: Failed to fetch
http://ppa.launchpad.net/webupd8team/java/ubuntu/dists/xenial/InRelease Temporary failure resolving 'ppa.launchpad.net'
W: Some index files failed to download. They have been ignored, or old ones used instead.