Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

In this photograph taken on April 1, 2015, an Indonesian resident and child walk away from an abandoned school building as Mount Sinabung erupts in Karo district on the Indonesian island of Sumatra. According to authorities about 3,500 people were displaced after the February 2014 eruption of Mount Sinabung volcano and many are still living in evacuation centers as the volcano remains active. (Photo by Sutanta Aditya/AFP Photo)

In this Wednesday, July 23, 2014 file photo, Omaha photographer Lane Hickenbottom photographs the night sky in a pasture near Callaway, Neb. With no moon in the sky, the Milky Way was visible to the naked eye. More than one-third of the world’s population can no longer see the Milky Way because of man-made lights, according to a scientific paper by Light Pollution Science and Technology Institute's Fabio Falchi and his team members, published on Friday, June 10, 2016. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

A soup for the students is pictured during an activity for the end of the school year at the Padre Jose Maria Velaz school in Caracas, Venezuela July 12, 2016. Due to the faltering socialist economy and the plunge in global oil prices, Venezuela has been in recession since early 2014. Due to the faltering socialist economy and the plunge in global oil prices, Venezuela has been in recession since early 2014. It suffers from the world's highest inflation and is experiencing shortages of basic goods, from milk to medicines. (Photo by Carlos Jasso/Reuters)

Former “The Hills” star Audrina Patridge and her on again, off again boyfriend Corey Bohan get into a huge fight after attending Matthew Morrison's Halloween Party at Hyde Nightclub in West Hollywood, California on October 25, 2014. Audrina and Corey, who recently split up this past summer, seemed to be in great spirits before the party started but afterwards it was a whole different story! The not so happy couple argued on a bench and at one point a visibly upset Audrina sat on the sidewalk crying! (Photo by FameFlynet)

A member of Sisters of the Valley, a non-religious international group founded in 2014 which has pledged to spread the gospel of the healing powers of cannabis, who uses the moniker “Sister Bernardet” online and asked not to give her name for fear of reprisal, smokes a joint at the Sisters of the Valley's farm on the outskirts of a village in central Mexico on September 3, 2023. (Photo by Raquel Cunha/Reuters)

Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)