Some Problem Ubuntu 14.04 about lost audio and system settings

Some Problem Ubuntu 14.04.md

• Missing System Settings after removing some packages (http://askubuntu.com/a/453441)

sudo apt-get install ubuntu-desktop

• Sound icon missing from top menu bar
  • http://askubuntu.com/a/471678
  • https://bugs.launchpad.net/ubuntu/+source/indicator-datetime/+bug/1228360

gsettings get com.canonical.indicator.sound visible

If the outcome is is "false", change it with the command:

gsettings set com.canonical.indicator.sound visible true

And then:

killall unity-panel-service