Competitors take part in the annual Mud Madness event at Foymore Lodge on April 22, 2018 in Portadown, Northern Ireland. The adult version of the event includes two laps of an 8km course through 25 obstacles while the kids event is run over 2kms. The race is in it's eleventh year and is sponsored by McVities Jaffa Cakes and event charity partner Marie Curie together with other numerous charities and fundraising groups. (Photo by Charles McQuillan/Getty Images)

A woman affected by tear gas is assisted during a May Day protest against austerity measures, in San Juan, Puerto Rico May 1, 2018. (Photo by Alvin Baez/Reuters)

Aerial photo taken on April 20, 2018 shows the view of advection fog above Qingdao, a coastal city in east China' s Shandong Province. (Photo by Lu Hui/Xinhua News Agency/Eyevine)

An Iran fan attends the Russia 2018 World Cup Group B football match between Morocco and Iran at the Saint Petersburg Stadium in Saint Petersburg on June 15, 2018. (Photo by Dylan Martinez/Reuters)

Cambridge students the morning after the Trinity and Jesus college May Balls in Cambridge, United Kingdom on June 19, 2018. Students at Cambridge University celebrate the end of the academic year with the May Balls. (Photo by South West News Service)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

A commercial airline landing at the Princess Juliana International Airport in St Maarten on July 9, 2018. Ukrainians Oleg Kolisnichenko, 36, and Yulia Nos, 25, have been blasted for the “stupid stunt” on Maho Beach, which lies next to the main airport on the Caribbean island of Saint Martin. The stunt was met with criticism rather than praise from social media users. (Photo by SWNS: South West News Service)

A bull savar (jockey) guides his bulls as he competes in a bull race on the outskirts of Islamabad, Pakistan July 1, 2018. (Photo by Faisal Mahmood/Reuters)