A US Army M1A2 SEP tank participates in the Strong Europe Tank Challenge 2017 at the military training area in Grafenwoehr, Germany, 12 May 2017. Six North Atlantic Treaty Organization (NATO) nations and partner nations, Austria, France, Germany, Poland, Ukraine and the USA are taking part in this competing exercise. (Photo by Christian Bruna/EPA)

In this Sunday, June 27, 2010 file photo two men compete in an ostrich race at Highgate ostrich farm in Oudtshoorn, South Africa. Clambering onto an ostrich for a ride used to be popular among tourists in a South African town of Oudtshoorn known of as the “ostrich capital of the world”. Not so much anymore. Two major ostrich farms in Oudtshoorn have stopped offering ostrich rides to tourists, responding to concerns about the birds’ welfare. A third farm is sticking with the feature, saying it is regulated and that ostriches do not experience discomfort. The Highgate farm, however, continues to offer ostrich rides. (Photo by Shuji Kajiyama/AP Photo)

Convicted murderer Hector Alvarado Mazariegos, right, drops to the ground as he is hit by bullets of a Guatemala firing squad in the public cemetery at Mazatenango, June 28, 1975. His companion, Rocael Ortiz, met the same fate a few seconds later. Both were convicted of murder. (Photo by AP Photo/Anzueto)

People fight for the ball as they take part in a mud football match during a festival for celebrating harvest in a village in Jinhua, Zhejiang Province, China September 24, 2017. (Photo by Reuters/China Stringer Network)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

Svetlana Tseyko feeds a 10-month-old moose named Grisha in the courtyard in the village of Abramy, some 160 km northwest of Minsk, on February 21, 2017. (Photo by Sergei Gapon/AFP Photo)

In this photograph taken on October 27, 2017 an Afghan woman collects saffron flowers after picking them in a field on the outskirt of Herat For years, Afghanistan has tried to give farmers alternatives such as fruit crops and saffron to wean them away from poppy farming – the lifeblood of the Taliban insurgency. International donors have splurged billions of dollars on counter- narcotics efforts in Afghanistan over the past decade, including efforts to encourage farmers to switch to other cash crops such as saffron. But those efforts have shown little results. (Photo by Hoshang Hashimi/AFP Photo)

A follower of the Afro-Brazilian religion Umbanda pays tribute for Iemanja, goddess of the sea, in Copacabana Beach in Rio de Janeiro, Brazil December 29, 2017. Hundreds of practitioners of Brazil's Afro-Brazilian Candomble and Umbanda faiths have gathered at Rio de Janeiro's Copacabana beach to honor Yemanja. Worshippers were mostly dressed in white as they launched their offerings to Iemanja: small boats with flowers and bowls with candles and fruits. (Photo by Ricardo Moraes/Reuters)