Students celebrate their A-level results at King Edward VI High School for Girls in Birmingham, England on August 18, 2016. The proportion of top grades achieved by A-level students across the UK has fallen for a fifth year in a row, and girls have caught up with boys in attaining A* grades. (Photo by Joe Giddens/PA Wire)

UConn students from Storrs, Conn., Gary Tu, Danny Wang and Victor Zheng, fish at Shenipsit Lake in Tolland, Conn. during sunset on Tuesday, August 19, 2014. (Photo by Jim Michaud/AP Photo/Journal Inquirer)

Abdulahi Yaroow, 13, smokes a cigarette while chewing khat at the same time in Mogadishu August 10, 2014. Grown on plantations in the highlands of Kenya and Ethiopia, tonnes of khat, or qat, dubbed “the flower of paradise” by its users, are flown daily into Mogadishu airport, to be distributed from there in convoys of lorries to markets across Somalia. Britain, whose large ethnic Somali community sustained a lucrative demand for the leaves, banned khat from July as an illegal drug. This prohibition jolted the khat market, creating a supply glut in Somalia and pushing down prices, to the delight of the many connoisseurs of its amphetamine-like high. (Photo by Thomas Mukoya/Reuters)

Jared Leto poses with fans for a selfie during the “Clear Channel Media and Entertainment” at the 2014 Cannes Lions on June 18, 2014 in Cannes, France. (Photo by Didier Baverel/WireImage)

Green algae sits on a beach in Kuwait City, Kuwait, 28 February 2017. The formation of green algae is a normal phenomenon that occurs every year at the shores of Kuwait. (Photo by Raed Qutena/EPA)

Workers look at exotic models and p*rn actresses standing on the top of a bus waving to people to promote the “Expo Sеx and Eroticism” adult exhibition in Mexico City, Mexico March 1, 2017. (Photo by Carlos Jasso/Reuters)

A reveller is tossed into the air as they celebrate the Holi spring festival in Kathmandu on March 12, 2017. The “Holi” festival of colours is a riotous celebration of the coming of spring and falls on the day after the full moon in early March every year. (Photo by Prakash Mathema/AFP Photo)

A displaced Iraqi girl, who fled her home, cries during a battle between Iraqi forces and Islamic State militants, near Badush, Iraq, March 16, 2017. (Photo by Reuters/Stringer)