Bonobo apes, primates unique to Congo and humankind's closest relative, groom one another at a sanctuary just outside the capital Kinshasa, Congo on October 31, 2006. (Photo by Finbarr O'Reilly/Reuters)

A Romanian female soldier adjusts her helmet before taking part in weapons training with US Marines female counterparts at the Capu Midia Surface to Air Firing Range, on the Black Sea coast in Romania, Monday, March 20, 2017. About 1,200 US and Romanian troops take part in the Spring Storm 17 exercise, meant to simulate defense of the Romanian Black Sea coastline and urban areas. (Photo by Vadim Ghirda/AP Photo)

Participants in the Grelka Fest at the Sheregesh resort in Tashtagolsky District of Kemerovo Oblast, Russia on April 22, 2017. Russian girls marked the end of the ski season with a record-breaking bikini ski festival at Siberia’s top winter resort, Sheregesh. Some 1,498 skiers and snowboarders undressed to impress in the annual event as they took to the pistes under blues skies and sunshine in a bracing temperature of just 5°C. (Photo by Grelka Fest/The Siberian Times)

Festival goers having fun at the Balaton Sound music festival in Zamardi next to the Lake of Balaton, 110 km (68 miles) west of Budapest, July 8, 2017. (Photo by Sandor Csudai)

Manchester City's Phil Foden celebrates after scoring his side's sixth goal during the Champions League round of 16 second leg, soccer match between Manchester City and Schalke 04 at Etihad stadium in Manchester, England, Tuesday, March 12, 2019. (Photo by Dave Thompson/AP Photo)

In this Thursday, March 28, 2019, photo, a “golden giant burger” is served at a restaurant of Hotel Grand Hyatt Tokyo in Tokyo. The $900 wagyu (Japanese-produced beef) burger was unveiled to commemorate the era change. What’s in a name? Quite a lot if you’re a Japanese citizen awaiting the official announcement Monday, April 1, 2019 of what the soon-to-be-installed new emperor’s next era will be called. It’s a proclamation that has happened only twice in nearly a century, and the new name will follow Emperor Naruhito, after his May 1 investiture, for the duration of his rule, attaching itself to much of what happens in Japan. (Photo by Kyodo News via AP Photo)

A Broto dancer prepares himself in a disused house of Bambari, in the centre of Central African Republic, before performing on March 14, 2019. The Broto, belonging to the Banda ethnic group, are known for their traditional dances accompanied by heavy horns made of tree roots. Today this tradition falls into disuse and its history is now forgotten by the new generations. (Photo by Florent Vergnes/AFP Photo)

Rwandan refugees cross the Rusumo border to Tanzania from Rwanda carrying their belongings, goats, mattresses and cows, May 30, 1994. The bloodshed that claimed 800,000 Tutsi and moderate Hutu lives began 25 years ago on April 7, 1994, when a plane carrying Rwandan President Juvenal Habyarimana, Burundi President Cyprien Ntaryamira and a French air crew was shot down. (Photo by Jeremiah Kamau/Reuters)