Buildings in Nogales, Mexico (R) are separated by a border fence from Nogales, Arizona, United Sates, October 9, 2016. Building a wall along the U.S.- Mexico border has been a contentious subject in this year's U.S. presidential election. In parts of California and Arizona, a wall already exists. It runs across rocky deserts, flowing sand dunes and miles of agricultural land. (Photo by Mike Blake/Reuters)

Vegetables, wood and charcoal are loaded onto the roof of a battered Peugeot on November 7, 2018 in Matadi, Democratic Republic of the Congo. From the port of Matadi to the capital Kinshasa, a 350 km road crosses the south-west of the Democratic Republic of Congo. (Photo by Junior D. Kannah/AFP Photo)

Russian Emergency Situations employees help a girl to bath in the icy water on Epiphany at the Church of the Holy Trinity in Ostankino near TV Tower in Moscow, Russia, Friday, January 18, 2019. Across Russia, the devout and the daring are observing the Orthodox Christian feast day of Epiphany by immersing themselves in frigid water through holes cut through the ice of lakes and rivers. Epiphany celebrates the revelation of Jesus Christ as the incarnation of God through his baptism in the River Jordan. (Photo by Alexander Zemlianichenko/AP Photo)

An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

Youths kick a gay rights activist during a protest against a proposed new law termed by the State Duma, the lower house of Parliament, as “against advocating the rejection of traditional family values” in central Moscow June 11, 2013. (Photo by Maxim Shemetov/Reuters)

A Pakistani feeds his goat wearing the words “Eid Mubarak” or “Eid Greeting”, to be slaughtered on the Muslim holiday of Eid al-Adha, or “Feast of Sacrifice”, in Islamabad, Pakistan on Tuesday, October 15, 2013. Muslims all over the world are celebrating Eid al-Adha by sacrificing sheep, goats, cows and camels, to commemorate the Prophet Abraham's readiness to sacrifice his son, Ismail, on God's command. (Photo by Anjum Naveed/AP Photo)

Supporters of the presidential candidate Muhammadu Buhari and his All Progressive Congress hits another supporter with a motorbike during celebrations in Kano, Nigeria March 31, 2015. (Photo by Goran Tomasevic/Reuters)