Internally displaced Syrians who fled Raqqa tie ropes for their tents in a camp in Manbij, Syria on April 6, 2017. (Photo by Rodi Said/Reuters)

A girl rides on a train as she takes part in the first edition of the No Pants Subway Ride in Bucharest, Romania, Sunday, January 11, 2015. The No Pants Subway Ride is an annual which was started in 2002 by Improv Everywhere in New York, the goal is for riders to get on the subway train dressed in normal winter clothes without pants and keep a straight face. (Photo by Vadim Ghirda/AP Photo)

An Estonian competitor cheers during the “World Medieval Fighting Championship – the Israeli Challenge” in Rishon Letzion near Tel Aviv January 22, 2015. Israel hosted the tournament on Thursday, which includes 14 competitors from seven different countries – France, Belarus, Denmark, Estonia, Russia, Ukraine and Israel. (Photo by Amir Cohen/Reuters)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

Smithsonian National Zoo biologist Leigh Pitsko releases a male lion cub for its swim test in the zoo habitat moat, in Washington May 6, 2014. Four, unnamed ten-week old lion cubs were tested today for their ability to swim and remove themselves from their zoo habitat moat. (Photo by Gary Cameron/Reuters)

Veterinarian William Guerra Neto (2nd R) and an assistant take measurements of two Amazonian manatees who are being rehabilitated after sustaining injuries from hunting and fishing nets at the Center of Amazonian Manatees at Amana Lake in Maraa, Amazonas state, Brazil, September 21, 2015. (Photo by Bruno Kelly/Reuters)

A Tyrannosaurus Rex dinosaur costume runs on the field as young boys play an exhibition soccer match during halftime of the MLS soccer game between the Los Angeles Galaxy and Seattle Sounders FC in Carson, California May 26, 2013. The dinosaur was on the field to promote the Natural History Museum of Los Angeles County. (Photo by Danny Moloshok/Reuters)

A Mercedes-Benz 300 SL “Gullwing” Coupe is displayed during an exhibition of vintage and classic cars by Bonhams auction house at the Grand Palais during the Retromobile week in Paris, France, February 8, 2017. (Photo by Benoit Tessier/Reuters)