Competitors take part in the 8th annual World Gravy Wrestling Championships at the Rose n Bowl Pub in Bacup, north west England on August 31, 2015. Contestants must participate in fancy dress and wrestle in a pool of Lancashire Gravy for 2 minutes whilst being scored for a variety of wrestling moves. (Photo by Oli Scarff/AFP Photo)

Protesting university students flee as police fire stun grenades outside Parliament in Cape Town, South Africa, Wednesday October 21, 2015. The protests are part of a wave of nationwide protests that have shut down many South Africa universities, which say they are struggling with higher operational costs as well as inadequate state subsidies. (Photo by AP Photo)

One of four Acehnese teen gets whipped for spending time in close proximity with her boyfriend who is not her husband, which is against Sharia law, in Aceh on April 18, 2017. Aceh on Sumatra island began implementing Sharia law after being granted special autonomy in 2001, an attempt by the central government in Jakarta to quell a long-running separatist insurgency. (Photo by Chaideer Mahyuddin/AFP Photo)

In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

A Tibetan man stirs butter tea made for the arriving guest during the function organised to mark Losar or the Tibetan New Year at a Tibetan Refugee Camp in Lalitpur February 19, 2015. Tibetans across the world marked the arrival of the New Year with prayers and festivities. (Photo by Niranjan Shrestha/AP Photo)

A man sits on his cart which he attached with National League for Democracy (NLD) party flags along a flooded street in Yangon September 30, 2015. Myanmar will hold a general election on November 8. (Photo by Soe Zeya Tun/Reuters)

A wild macaque monkey eats fruit dropped by pedestrians in a suburb of Kuala Lumpur, Malaysia, on June 11, 2013. (Photo by Mohd Rasfan/AFP Photo)