Employees stand near an airframe for the second Antonov-225 Mriya plane at Antonov aircraft plant in Kiev, Ukraine, September 7, 2016. Ukraine hopes to attract $500 million of investment from China to complete an updated version of the world's biggest aircraft, the Antonov-225 Mriya, the president of manufacturer Antonov said on Wednesday. (Photo by Valentyn Ogirenko/Reuters)

A rat being trained by the Cambodian Mine Action Centre (CMAC) is pictured on an inactive landmine field in Siem Reap province July 9, 2015. Gambian pouched rats were deployed to Cambodia from Tanzania in April by a Belgian non-profit organization, APOPO, to help clear mines. They've been trained since they were 4 weeks old. Cambodia is still littered with landmines after emerging from decades of civil war, including the 1970s Khmer Rough “Killing Fields” genocide, leaving it with one of the world's highest disability rates. APOPO has used the rodents for mine-clearing projects in several countries, including Angola, Mozambique, Thailand, Laos, and Vietnam. (Photo by Samrang Pring/Reuters)

19 giant panda cubs, all born this year, meet the public at the Shenshuping Base of the China Conservation and Research Centre for the Giant Panda on October 13, 2017 in Ngawa Tibetan and Qiang Autonomous Prefecture, China. So far China Conservation and Research Centre for the Giant Panda has successfully bred 42 giant pandas this year. (Photo by VCG/VCG via Getty Images)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

In this February 14, 2019 photo, a newlywed couple kisses while posing for photos at one of several free sets placed for newlyweds to take cell phone photos of themselves following a mass wedding ceremony on Valentine's Day in Mexico City. Hundreds of couples of all ages, many with their children, gathered to legally tie the knot in a mass ceremony in the capital's Venustiano Carranza neighborhood. (Photo by Rebecca Blackwell/AP Photo)

Volunteers of a Wild Nature Preservation center release a group of owl chicks from the Toro Mountain in Menorca, Balearic Islands, Spain, 31 July 2019. (Photo by David Arquimbau Sintes/EPA/EFE/Rex Features/Shutterstock)

Andre Krumbiegel drives in a «SIL» pointed plough through the pink fog of a smoke body in Saxony, Germany on October 2, 2019. The occasion is the forthcoming Eastern Bloc meeting on 6 October in Großhartmannsdorf, to which motor vehicles and commercial vehicles from former socialist countries can be brought, exhibited and demonstrated. Photo by Sebastian Kahnert/dpa-Zentralbild/Keystone)

A river otter (lontra longicaudis) of 6-weeks-old looks in the mirror during a bath in the Animal Welfare Unit of the Zoo in Cali, Colombia, on October 22, 2019. The baby otter was found abandoned brought to the Cali Zoo for breeding, for its extensive experience in raising these species. According to the International Union for Conservation of Nature the river otter (lontra longicaudis) are in danger of extinction, because of mining, agriculture, pollution of rivers and housing construction in their habitat. (Photo by Luis Robayo/AFP Photo)