An activist kicks the shields of the military police officers during a demonstration in the military zone of the 27th infantry battalion in Iguala, Guerrero, January 12, 2015. Activists and relatives of the 43 missing trainee teachers from Ayotzinapa's teacher training college broke into the military zone, located less than a mile from where the students went missing, in an attempt to look for the missing students.The remains of only one of the 43 students has been identified so far. (Photo by Jorge Dan Lopez/Reuters)

A Palestinian youth jumps with a sword as he demonstrates his ninja-style skills for the photographer in front of the ruins of buildings, that were destroyed in 2014 war, in the northern Gaza Strip January 29, 2016. The youths, who have been receiving martial arts training at local clubs in Gaza for the past two years, decided to form a team to hold regular shows in the hope that the publicity generated will eventually lead to them being invited to participate in international contests. (Photo by Mohammed Salem/Reuters)

People gather at the site of a train derailment near Beni Suef, Egypt, Thursday, February 11, 2016 that injured dozens of people were injured as it was traveling north toward Cairo. Railroad accidents due to negligence are common in Egypt. Egyptians have long complained that the government has failed to deal with the country's chronic transport problems. (Photo by Samer Abdallah/AP Photo)

A member of the National Gendarmerie Intervention Group (GIGN) deactivates a bomb from a supposed terrorist during a training exercise in the event of a terrorist attack in collaboration with Recherche Assistance Intervention Dissuasion (RAID) and Research and Intervention Brigades (BRI) in presence of the French Interior minister Bernard Cazeneuve at la Gare Montparnasse, in central Paris on April 20, 2016. (Photo by Miguel Medina/Reuters)

Dancers perform on stage during the Crazy Horse Paris “Forever Crazy” Media Call at The MasterCard Theatres at Marina Bay Sands on October 11, 2017 in Singapore. Forever Crazy consists of a series of highly aesthetic and visual tableaus presented by a classically trained dancers clad only in textured lighting and projection. The show runs from 11 October 2017 till 22 October 2017 in Singapore. (Photo by Suhaimi Abdullah/Getty Images)

Aerial view of CRH bullet trains setting out ahead of Spring Festival travel rush on January 31, 2018 in Hefei, Anhui Province of China. About 2.98 billion trips will be made during the 40-day Spring Festival travel rush. China will take multiple measures to ensure a smooth Spring Festival travel rush. (Photo by VCG/VCG via Getty Images)

Female Naval Academy plebes perform push ups with a twelve foot log on top of them during the annual Sea Trials May 17, 2016 at the Naval Academy in Annapolis, Maryland. The Naval Academy freshman class endures 14 hours of rigorous physical and mental challenges during the annual Sea Trials training exercise as part of the culmination of their freshman year at the academy. (Photo by Win McNamee/Getty Images)

Competitors Hope Garcia (L) and Francesca Esker during the newly reintroduced Muscle Beach Vintage Swimsuit competition at Venice Beach, California on May 30, 2016. Venice is one of two historic bodybuilding locations and took over as the most famous spot when the nearby Santa Monica Muscle beach was shutdown due to overcrowding. California Governor and actor Arnold Schwarzenegger used to be a regular amongst the many famous bodybuilders and actors who have trained there and still makes an occasional appearance. (Photo by Mark Ralston/AFP Photo)