An armed youth loyal to the Houthi movement takes part in a protest against the Saudi-backed exiled government deciding to cut off the Yemeni central bank from the outside world, in the capital Sanaa, Yemen August 25, 2016. (Photo by Mohamed al-Sayaghi/Reuters)

Expedition 44 flight engineer and NASA astronaut Scott Kelly seen inside the Cupola, a special module which provides a 360-degree viewing of the Earth and the International Space Station. Kelly is one of two crew members spending an entire year in space. (Photo by Scott Kelly/NASA)

A man exercises in the early morning on a hilltop overlooking Kabul, Afghanistan March 3, 2016. (Photo by Mohammad Ismail/Reuters)

Friends outside the convention center during opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by WENN/SIPA Press)

Belarusian schoolchildren, who are members of a pro-government Young Pioneer movement, perform with drums as they take part in a meeting to mark the 95th anniversary of their organisation in Minsk, Belarus May 19, 2017. (Photo by Vasily Fedosenko/Reuters)

A dancer warms up backstage before the final of the 46th Prix de Lausanne, in Lausanne, Switzerland, 03 February 2018. Launched in 1973, the Prix de Lausanne is an international dance competition for young dancers aged 15 to 18. Closing the six-day event, prizes are awarded to the best of 21 finalists consisting of scholarships granting free tuition in a world-renowned dance school or dance company. (Photo by Valentin Flauraud/EPA/EFE)

Dan Copeland, left, and Alex Morneau of Biddeford, Maine, former high school cheerleaders, perform back flips while enjoying the record breaking heat, Thursday, May 18, 2017, at Old Orchard Beach, Maine. The temperature climbed well into the 90s in many locations throughout the state. (Photo by Robert F. Bukaty/AP Photo)

Chinese workers maintain an Animatronic Dinosaurs at Gengu Dinosaurs Science and Technology company on November 13, 2019 in Zigong, Sichuan Province, China. There are hundreds of simulated dinosaur manufacturers in Zigong City. It is the largest simulated dinosaur manufacturing in China. It accounts for 95% of mainland China's production and 85% of the world's total. Its products are exported to more than 100 countries. (Photo by Lintao Zhang/Getty Images)