LOS ANGELES - Scarlett Johansson had just two days to master the Russian language for her role in The Avengers movie. The Hollywood actress reprises her Iron Man 2 character Natasha Romanoff, aka Black Widow, in the blockbuster, and got to grips with her superhero’s native tongue for some key scenes. However, Johansson soon realised she had just 48 hours to work with a dialect coach to learn some tricky Russian speeches.