Which word is missing from the title of the swimming event held at the 2015 World Aquatics Championships in which Christopher Walker-Hebborn, Adam Peaty, Siobhan-Marie O’Connor and Francesca Halsall won the gold medal for Great Britain - 4 × 100 metre ______ medley relay?
Great Britain at the 2015 World Aquatics Championships ten medals, the highest ever for the nation at a FINA World Aquatics Championships. Simultaneously, with his silver medal from 2013, Hunt became the most successful male high diver since the event was brought into the World Aquatics Championships. Adam Peaty became the first British swimmer to ever win three gold medals at a global championships, Worlds or Olympic, with victories in the 50 metre and 100 metre breaststroke events and the 4 x 100 metre mixed medley relay. James Guy won the first ever gold medal in male freestyle for Great Britain at a World Championships in the 200
Great Britain at the 2015 World Aquatics Championships qualify by finishing in the top two of the national championships, having gained the GB qualifying A standard set by British Swimming in the relevant final. Great Britain consists of 30 swimmers (16 men and 14 women). Among the official roster featured European and Commonwealth Games champions Jazmin Carlin, Chris Walker-Hebborn, and Adam Peaty, who overhauled the 58-second barrier to set a new world record in the 100 m breaststroke at the national trials. The championships were a qualification event for the relay races at the 2016 Summer Olympics, and Great Britain qualified for five of the six relays in