A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

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)

Reverend Simon Davis prays with the dancers before the Abbots Bromley Horn Dance in Abbots Bromley, Britain, September 12, 2016. The Abbots Bromley Horn Dance is an English folk dance dating back to the Middle Ages. (Photo by Darren Staples/Reuters)

Swiss rescue workers wheel a wounded person on a stretcher after two regional trains crashed head on near Granges-Pres-Marnand near Payerne in western Switzerland July 29, 2013. The two trains collided in the Swiss canton of Vaud on Monday evening, injuring about 40 people, four seriously, Swiss news agency ATS reported. There was no immediate report of any deaths in the crash. (Photo by Denis Balibouse/Reuters)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

A man rides a bike on a submerged road alongside a boat at Demra area in Dhaka on July 24, 2020. As many as 20 districts including the latest additions Chandpur, Brahmanbaria, and Naogaon have so far been hit with the worsening flood situation across Bangladesh and many more areas might be inundated if the situation does not improve soon, said Flood Forecasting and Warning Centre (FFWC). (Photo by Sultan Mahmud Mukut/SOPA Images/LightRocket via Getty Images)

A young girl sits on a mat, as worshippers arrive to pray to mark the Muslim Eid-al-Adha (Festival of Sacrifices) without observationg precautionary measures to curb the spread of COVID-19, in Kara, Ogun State in southwest Nigeria, on July 31, 2020. Nigerian Muslim faithfuls joined their counterparts across the world to celebrate Eid-El-Adha, Islamic festival of sacrifice. (Photo by Pius Utomi Ekpei/AFP Photo)