A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela' s angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro' s plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Juan Barreto/AFP Photo)

Martin Herrera, 58, who has had a love for roosters since his childhood, and has spent the last 20 years domesticating and training them, walks with his favorite rooster “Paquito” in San Jose, Costa Rica April 27, 2017. (Photo by Juan Carlos Ulate/Reuters)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

A photo taken by a member of the County Durham and Darlington fire and rescue Service of a coach on fire on the A1 in County Durham, England on March 2, 2017. Passengers were evacuated safely before flames engulfed the vehicle. (Photo by County Durham and Darlington Fir/PA Wire)

An air tanker drops fire retardant on flames as firefighters continue to battle against the Detwiler fire in Mariposa, California on July 19, 2017. The Detwiler fire is currently at 7 percent containment and has burned more than 45,000 acres and destroyed eight structures. (Photo by Josh Edelson/AFP Photo)

French celebrities show off dresses made with chocolate at the Paris chocolate fair on October 27, 2021 in Paris, France. From left: Gennifer Demey, a weather forecaster; Isabelle Vitari, an actress; and Alicia Aylies, Miss France 2017. (Photo by Laurent Viteur/Getty Images)

An attendee tries Acton's RocketSkates at the 2015 International CES at the Sands Expo and Convention Center on January 6, 2015 in Las Vegas, Nevada. The motorized skates that you strap to your shoes are powered by Lithium Ion batteries and can go up to 12 mph. (Photo by Ethan Miller/Getty Images)