Can I pass an argument as ?xxx=arg
As long as you have something (a custom module, for example) looking for the arguments, yes, you can pass as many arguments as you want.

Depending on the size of the articles, however, instead of requiring a page refresh, I would suggest either an AJAX call (more complicated) or using jQuery (less complicated) to hide the content, and simply show it on demand. If the articles are large though, the jQuery option would be cumbersome and slow the page, since it would load all of the material at page load.