Students walk to school on the first day of their new school year in Giza, south of Cairo, Egypt September 25, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

A baboon clings to the leg of an internally displaced boy at a camp on the outskirts of the town of Qol Ujeed, on the border with Ethiopia, Somaliland April 17, 2016. Across the Horn of Africa, millions have been hit by the severe El Nino-related drought. In Somaliland and its neighbouring, also semi-autonomous, Puntland region, 1.7 million people are in need of aid, according to the United Nations. In Somaliland itself, the most affected areas include the northwest Awdal region bordering Ethiopia. (Photo by Siegfried Modola/Reuters)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)

Traditional trumpeters perform during the durbar festival on the second day of Eid-al-Fitr celebrations in Nigeria's northern city of Kano, July 7, 2016. The Durbar festival begins with prayers, followed by a parade of the Emir and his entourage on horses, accompanied by music players, and ending at the Emir's palace. The Durbar festival had been in hausaland for more than 500 years. It was introduced by sarki muhammadu rumfa of kano in the late 14th century, as a way of demonstrating military power and skills before going to war. The festival is also an opportunity for local leaders to pay homage to emir throughout the jahi cheering. (Photo by Akintunde Akinleye/Reuters)

Two stallions confront each other at a horse fighting contest in Rongshui, China. More than 30 horses from surrounding regions took part in the traditional activity of the Lantern festival. (Photo by China Foto Press)

A Hindu devotee lies on a road as she worships the Sun god during the religious festival of Chhath Puja in Kolkata, India October 26, 2017. (Photo by Rupak De Chowdhuri/Reuters)

Eighty one-year-old Sakon Haba (L) wearing loin cloth walks past a police station after he bathed in ice-cold water at the Teppozu Inari shrine in Tokyo January 11, 2015. According to organizers, about 100 participants took part in the Shinto ceremony to purify their souls and wish for good health in the new year. (Photo by Toru Hanai/Reuters)

Google's vice president Alan Eustace looks out of his spacesuit into the stratosphere prior to a record-breaking skydive over New Mexico, in this still image taken from video October 24, 2014, a handout courtesy of the Paragon Space Development Corporation. Eustace was lifted up 135,890 ft (41,420 metres) by an enormous balloon while wearing a specially designed pressurized space suit, the Paragon Space Development Corporation said. Eustace remained in a free fall for approximately 4.5 minutes before landing safely nearly 70 miles (43.4 kms) from his launch point, setting a world record for the highest skydive and breaking the sound barrier in the process. Eustace landed safely on the ground just 15 minutes after he was lifted into the air. (Photo by Reuters/Paragon Space Development Corporation)