Avengers European premiere Scarlett Johansson poses for photographs as she arrives for the European premiere of Avengers Assemble at The V...

Avengers European premiere

Scarlett Johansson poses for photographs as she arrives for the European premiere of Avengers Assemble at The Vue, Paddington, London, April 19, 2012. REUTERS/Paul Hackett

Scarlett Johansson poses for photographs as she arrives for the European premiere of Avengers Assemble at The Vue, Paddington, London, April 19, 2012. REUTERS/Paul Hackett

Scarlett Johansson, Robert Downey Jr, Chris Hemsworth and fellow cast members of 'Avengers' wowed fans on the red carpet in London, for the European premiere.