American citizen with Carte de Sejour - Can I work in other EU countries?

I am an American doing my masters in France which requires an internship. I have trouble finding an internship in France due to non-fluency of French. Is the Carte de Sejour enough to work in other EU countries or the UK? what other papers do I need or what do I have to do (considering I already have the carte de sejour) to be eligible to work in another country?