NFL player Rob Gronkowski, of the New England Patriots, from second left, accepts the best comeback athlete award with his brothers, NFL free agent Chris Gronkowski and former NFL player Dan Gronkowski at the ESPY Awards at the Microsoft Theater on Wednesday, July 15, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

Su Daocheng rides his home-made mechanical horse vehicle on a street in Shiyan, Hubei province January 18, 2015. Su spent 2 months making this 1.5 metre high and 2 metre long horse, which weighed 250 kilograms with 4 legs and 2 supportive wheels, local media reported. (Photo by Reuters/Stringer)

A child poses on the runway during a party hosted by Chasing Fireflies to introduce Gwen Stefani's Harajuku Lovers children's collection at Duff's Cakemix on September 24, 2015 in West Hollywood, California. (Photo by Frazer Harrison/Getty Images for Chasing Fireflies)

Second placed Kalex Moto2 Tito Rabat (rear R) of Spain and third placed Kalex Moto2 Alex Rins of Spain spray with champagne during the award ceremony for the Czech Grand Prix in Brno, Czech Republic, August 16, 2015. (Photo by David W. Cerny/Reuters)

America in the 1970s: Texas. Motorcyclist loading his possessions onto a truck with the help of his friends in Leakey, May 1973. (Photo by Marc St. Gil/NARA via The Atlantic)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

A Herero man holds the head of a freshly butchered cow, killed to supply meat for a funeral, 2012. (Photo by Jim Naughten, courtesy of Klompching Gallery, New York)

Iranian skiers rest at the Dizin ski resort, northwest of Tehran January 15, 2016. (Photo by Raheb Homavandi/Reuters/TIMA)