Best foreign language to learn for a physicist

Hi everyone. I know this question might have been asked many times, but still I would like to get some advice. I'm going to study physics in the UK as undergrad, and right now am interested in getting a PhD after graduation (I'm still open to any options including the US, the UK or in Europe). I would like to know which language (Spanish, French or German) will help me most in future (PhD, postdoc, working in industry, etc)?



thanks