A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)

Firefighters use flashlights to search for survivors among the rubble of collapsed buildings after a landslide hit an industrial park in Shenzhen, Guangdong province, China December 20, 2015. (Photo by Tyrone Siu/Reuters)

A woman poses for a photograph in front of a 3D painting at HK 3D Museum in Hong Kong June 26, 2014. (Photo by Tyrone Siu/Reuters)

This handout picture taken and released by the Borneo Orangutan Survival Foundation (BOSF) on October 26, 2015 shows baby orangutans, which had previously suffered from respiratory problems, playing at a nursery in the rehabilitation centre operated by the BOSF on the outskirts of Palangkaraya in Central Kalimantan. Endangered orangutans are falling victim to a devastating haze crisis that has left them sick, malnourished and severely traumatised as fires rage through Indonesia's forests, reducing their habitat to a charred wasteland. (Photo by AFP Photo/Borneo Orangutan Survival Foundation/Indrayana)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)

A picture made available on 07 March 2016 shows visitors petting and holding a Fennec fox, native to the Sahara, in the petting room at the Little Zoo Cafe, a business built to capitalize on Thais' love for exotic animals, and food, on the outskirts of Bangkok, Thailand, 05 March 2016. The cafe boasts Fennec foxes, Meerkat, native to parts of Africa, Silver Fox, Raccoon and Chinchillas, along with a menu of Thai food and Cheesecake, among other sweet deserts. Nature is a faraway fantasy in the bustling exhaust-filled cement city of Bangkok, fuelling a demand to own and be close to exotic pets. The trend to be near to a species that was once wild, in a city environment, far from the natural setting, has drawn criticism but continues to grow. (Photo by Barbara Walton/EPA)

A woman takes part in the procession of the “Virgem da Atalaia” procession during Holy Week at Alcochete, near Lisbon, Portugal March 27, 2016. Women ride on donkeys during the “Virgem da Atalaia” procession, that has been held annually for about 400 years. In the past, only single women rode the donkeys to ask for help from the Virgin to find a husband. (Photo by Rafael Marchante/Reuters)

A monkey jumps from a branch at Yangon Zoological Gardens in Yangon, Myanmar, 06 April 2016. Yangon Zoological Gardens (Yangon Zoo) is the oldest and second largest zoo in Myanmar. (Photo by Lynn Bo Bo/EPA)