NG-show based on select list

I am trying to get items to only show up if something is selected in a select list. I am trying something like this

<input ng-show="myDropDown==''" type="text">

I basically want logic saying if the drop down has anything selected, show this ^. I found that example for specifying the option selected, however I would just like do say if anything is selected show, and if nothing has been selected, hide.

There is a catch, however, these drop downs will be re-generated with $http based on other clicks, and it would be ideal if this was done that the text would hide. Any ideas? Thanks!

Copyright Notice：Content Author:「ajmajmajma」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/25413678/ng-show-based-on-select-list