Graduates jump as they pose for photographs in front of the Tiananmen Gate and the giant portrait of late Chinese Chairman Mao Zedong, on the Tiananmen Square in Beijing, June 19, 2014. (Photo by Reuters/Stringer)

In this September 17, 2010 file photo a little brown bat is photographed in La Crosse Wis. Researchers for the first time found that little brown bats appear to be showing resistance to white-nose syndrome, which has killed millions of bats across North America. (Photo by Peter Thomson/La Crosse Tribune via AP Photo)

Ethnic Miao women wearing traditional costumes take part in a parade during the traditional Lusheng (reed-pipe wind instrument) festival in Gulong, Guizhou province, China November 15, 2017. (Photo by Reuters/China Stringer Network)

A guest arrives before the Blumarine show during Milan Fashion Week Spring 2019 in Milan, Italy, September 21, 2018. (Photo by Stefano Rellandini/Reuters)

Police officers laugh as Greenpeace activists create a burnt smoldering rain-forest with a lifelike animatronic orangutan at the headquarters of Oreo cookies, in protest over their use of palm oil on November 19, 2018 in Uxbridge, England. Greenpeace is calling on the makers of Oreo to stop buying palm oil from Wilmar, the largest palm oil producer, who they say have destroyed 70,000 hectares of Indonesian rain forest in the last two years. (Photo by Chris J. Ratcliffe for Greenpeace via Getty Images)

Aerial view over mud and waste from the disaster caused by dam spill in Brumadinho, Minas Gerais, Brazil, 26 January 2019. At least nine people have died and 300 are missing after a tailings dam burst at the Feijao mine in southeastern Brazil owned by Vale, the world's largest iron-ore producer, the Minas Gerais state government said. The dam in Brumadinho near Belo Horizonte broke on 25 January at around mid-day, unleashing a river of sludge that destroyed some nearby houses. (Photo by Antonio Lacerda/EPA/EFE)

A young Sandinista guerrilla takes aim with his 45 pistol as he stands waiting to do combat with the Nicaraguan National Guard in Managua June 23, 1979. The guerrillas still occupy major parts of the Capitol City. (Photo by McLendon/AP Photo)

Men push a car stucking in the mud on a motorway in Nimba County, Liberia, 28 July 2019. Most highway roads in the rural parts of the country are unpaved. The government of President George Weah has promised to build roads to connect all big cites of Liberia. (Photo by Ahmed Jallanzo/EPA/EFE)