There are a lot of English (or sounds like English, but taken from, for example, Latin) words in Russian language. Much more than you can imagine. Computer, file, forum, site, freelance, startup, chat, blog... in short almost all computer terms... tank, machine, automobile, stand, crystal, label, brand, summit, telephone, calculator, astronomy, philosophy, mathematics, manager, director, design... And this is only off the top of my head.

Concerning a most difficult language in the world, I think it is Japanese.