People try to board a goverment bus during the second day of a suspension of public transport services in Apopa, El Salvador July 28, 2015. Violent gangs in El Salvador ordered bus drivers to strike on Monday in a conflict that has killed six people and left thousands of commuters stranded on the streets of the Central American capital, police and bus company officials said. (Photo by Jose Cabezas/Reuters)

A workman jokes besides a work entitled “Monkey Detonator” by Banksy at Bonhams Auction house on September 16, 2011 in London, England. The piece makes up part of the “Urban Art” sale, and is expected to fetch between £70,000 - £90,000 GBP when it goes under the hammer on September 21, 2001 at Bonhams Auction house in London. (Photo by Dan Kitwood/Getty Images)

The Last Bell (we mean the bell that informs the pupils about the beginning or the ending of the lessons) is the traditional feast of the Russian pupils who leave the school. The Last School Bell feast occurs in the end of May, when the school year has already finished, but the final examinations have not begun yet. Luhansk (also known as Lugansk – a city in southeastern Ukraine), 2010. (Photo by X-F@ctor's bloG)

Malawian Saw-wa, 33, (L) and Yupin Saw-wa, 28 who lost their daughters, cry near a burnt building at the Pitakkiat Wittaya School in the northern province of Chiang Rai, Thailand, May 23, 2016. (Photo by Athit Perawongmetha/Reuters)

Revelers dressed as Santa Claus or in festive costumes arrive for the start of SantaCon 2018 in New York City December 8, 2018. SantaCon is an annual event where people dress as Santa Claus or other Christmas characters parade in several cities around the world. (Photo by Timothy A. Clary/AFP Photo)

An internally displaced girl stands on an abandoned railway tracks beside a makeshift refugee camp in Sinjar town, in Idlib province, Syria November 20, 2015. (Photo by Ammar Abdullah/Reuters)

Damaged buildings stand in the rebel-controlled area of Maaret al-Numan in Idlib province, Syria September 6, 2016. (Photo by Ammar Abdullah/Reuters)

Islamic female students practice the ancient Thai art of “Krabi Krabong” taught as a sport at the Darunsat Wittaya school on August 16, 2011 in Saraburi, Thailand. (Photo by Paula Bronstein/Getty Images)