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)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

Spectators dressed as leprechauns attend St Patrick's Day parade in Dublin on March 17, 2014. (Photo by Peter Muhly/AFP Photo)

A Chinese man uses an old film camera to take a picture of relatives near the Forbidden City on March 27, 2014 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

A country music fan cools off in the wind on the second day of the Stagecoach country music festival in Indio, California April 26, 2014. (Photo by Mike Blake/Reuters)

Two stags fight in a wildlife park in Aurach near Kitzbuehel, in the Austrian province of Tyrol. (Photo by Kerstin Joensson/Associated Press)

A Syrian refugee man (obscured) moves boxes of goods at his shop in Zaatari refugee camp near the border with Syria, in Mafraq, Jordan October 15, 2016. (Photo by Ammar Awad/Reuters)

A driver steers a lorry laden with bags of plastic bottles across a recycling yard at the outskirts of Beijing, China, August 19, 2016. As authorities try to control Beijing's burgeoning population and capitalize on skyrocketing land prices, scrap collectors say they are being pushed out despite playing a vital role in China's unique recycling ecosystem. (Photo by Thomas Peter/Reuters)