Question: Anna Guseva is a Russian distance swimmer, she competed in the Women's marathon 10 kilometre, finishing in 10th place, in which 2012 major international multi-sport event celebrated in the tradition of the Olympic Games, as governed by the International Olympic Committee (IOC)?
Sentence (from "2012 Summer Olympics"): The first event, the group stage in women's football began on 25 July at the Millennium Stadium in Cardiff, followed by the opening ceremonies on 27 July.
Relevant evidence: No