Girls dressed in traditional costumes run as men throw water on them as part of Easter celebrations during a presentation to the media in Mezokovesd, Hungary, April 13, 2017. (Photo by Laszlo Balogh/Reuters)

A girl is splashed with water by boys following a Polish Wet Easter Monday tradition, in Wilamowice, Poland, Monday, April. 17, 2017. (Photo by Jarek Praszkiewicz/AP Photo)

Aerobatic aircrafts fly during a performance at the Airshow Zhengzhou 2017 in Zhengzhou, capital of central China's Henan Province on April 27, 2017. The 5-day air show kicked off in Zhengzhou on Thursday, aiming to build a general aviation gathering center for business and communications. (Photo by Li An/Xinhua via ZUMA Wire)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

Eagle Prime (MK3), a giant robot by MegaBots Inc. which manufactures giant piloted humanoid fighting robots headquartered in Berkeley, California on October 18, 2017. (Photo by Courtesy Michael Mauldin/Reuters/MegaBots Inc)

Undercover Israeli police arrest a Palestinian demonstrator during clashes following protests against U.S. President Donald Trump's decision to recognize Jerusalem as the capital of Israel, in the West Bank city of Ramallah, Wednesday, December 13, 2017. (Photo by Nasser Shiyoukhi/AP Photo)

Competitors in the Big Air challenge at the Proryv-2016 festival of extreme sports in Moscow, Russia on March 27, 2016. (Photo by Xinhua/Rex Features/Shutterstock)

Participants in traditional dress ride on horseback as they enjoy the atmosphere at the Feria de Abril (April's Fair) on April 12, 2016 in Seville, Spain. The Feria de Abril has a history that dates back to 1857 and takes place a fortnight after Easter each year. The origin of the fair was a cattle market but the event quickly turned its goal from commerce to having fun. More than 1 million local and international participants are expected to attend the Feria de Abril. (Photo by David Ramos/Getty Images)