###### Ubuntu Main Repos
deb http://us.archive.ubuntu.com/ubuntu/ xenial main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial main universe

###### Ubuntu Update Repos
deb http://us.archive.ubuntu.com/ubuntu/ xenial-security main universe
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates main universe
deb http://us.archive.ubuntu.com/ubuntu/ xenial-backports main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-security main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-backports main universe