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)

A farmer seen harvesting his crops while Mount Sinabung spewing out volcanic ash on July 4, 2017 in North Sumatera, Indonesia. The increased volume of lava dome that reaches one million eight hundred cubic meters, said volcanologist, through radio communications, do not dampen the activities of the people around sinabung, such as farming, harvesting their crops, picking up objects that are still left behind, or just take a picture while walking around near mount Sinabung. (Photo by Sabirin Manurung/Pacific Press/Barcroft Images)

Participants in the 3rd Annual Amber Rose SlutWalk in Los Angeles, California. October 1, 2017. The event seeks to highlight issues such as: gender equality, ending rape culture, victim blaming and body shaming. (Photo by Ronen Tivony/NurPhoto via Getty Images)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

11-year-old Balinese dancer girl Intan puts on makeup before she performs Mergapati Dance at a village event in Banjar Wangaye Kelod, Denpasar, Bali, Indonesia on November 19, 2017. To preserve traditional dances and culture, Balinese train their children to learn various traditional dances from childhood. (Photo by Mahendra Moonstar/Anadolu Agency/Getty Images)

Indian Air Force officers stretch before taking part in full dress rehearsal for India's Republic Day parade in Kolkata, January 23, 2018. (Photo by Rupak De Chowdhuri/Reuters)

Aegean airlines air hostesses take selfies after a news conference in Athens, Wednesday, March 28, 2018. In a deal worth up to $5 billion, Greek airline Aegean says it will buy 30 new Airbus aircraft, with the option of an additional 12, to upgrade its fleet as the country expects to break tourism records. The signing of the final purchase agreement is expected in June. (Photo by Petros Giannakouris/AP Photo)