An Afghan refugee girl shows her younger brother a calf in a slum on the outskirts of Islamabad, Pakistan, Friday, February 6, 2015. (Photo by Muhammed Muheisen/AP Photo)

An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

Iraqi pro-government forces fire an anti-tank cannon near al-Sejar village, north-east of Fallujah, on May 25, 2016, as they take part in a major assault to retake the city from the Islamic State (IS) group. Iraqi forces, consisting of special forces, soldiers, police, paramilitary-fighters and pro-government tribesmen, launched a major assault to retake Fallujah, the scene of deadly battles during the US occupation and one of the toughest targets yet in Baghdad's war on the Islamic State group. (Photo by Ahmad Al-Rubaye/AFP Photo)

Girls bath inside a drum on a hot summer day at a field in New Delhi, April 18, 2017. (Photo by Adnan Abidi/Reuters)

Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

Medical staff members wearing protective clothing to help stop the spread of a deadly virus which began in the city, arrive with a patient at the Wuhan Red Cross Hospital in Wuhan on January 25, 2020. The Chinese army deployed medical specialists on January 25 to the epicentre of a spiralling viral outbreak that has killed 41 people and spread around the world, as millions spent their normally festive Lunar New Year holiday under lockdown. (Photo by Hector Retamal/AFP Photo)

Hundreds of students take part in the traditional Raisin Monday foam fight on St Salvator’s Lower College Lawn in Scotland on October 21, 2019. The messy display is the culmination of a weekend of festivities where first years say thank you to their more senior student “parents” for mentoring them. (Photo by Jane Barlow/PA Images via Getty Images)