Read the passage carefully and choose the correct answer.

Sport is one of the UK’s most popular leisure activities, with two-thirds of all adults taking part in one or more sporting activities. Sadly, this is not true for children and young adults. Of all sporting activities, walking is by far the most popular for men and women of all ages. While men tend to dominate golf and ‘cue sports’ such as snooker and billiards, women generally prefer swimming, keep-fit classes and yoga. The UK claims to be among the top five most successful nations in world sport.

UK sportsmen and sportswomen hold over 50 world titles in a variety of sports, such as professional boxing, modern pentathlon, rowing, snooker, squash and motorcycle sports. The Government's view is that sport is an important component of regeneration and can have a beneficial effect in helping the development of run-down areas.

(Source: http://gepeskonyo.btk.elte.hu)

UK sportsmen and sportswomen hold over 50 world titles in _______.