“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

A woman walks past a giant Pac-Man in Tokyo's Shinjuku area, Wednesday, August 12, 2015. The three-meter (about nine feet and 10 inches)-tall Pac-Man and other video game characters, made of Lego bricks, were on display to promote the upcoming movie “Pixels”. (Photo by Ken Aragaki/AP Photo)

Switzerland's Belinda Bencic celebrates after defeating Czech Republic's Marketa Vondrousova during their Tokyo 2020 Olympic Games women's singles tennis final match at the Ariake Tennis Park in Tokyo on July 31, 2021. (Photo by Yara Nardi/Reuters)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

A visitor takes a photo of a boulder plastic made of synthetic material called “To be in Limbo” hangs from the ceiling of the 20 meter high Jesuit Church in Vienna, Austria, Tuesday, November 25, 2014. The eight meter high, hollow and 700 kilogram heavy sculpture from the artists group Steinbrener/Dempf and Huber is supposed to symbolize faith and its threatening moments. The installation will remain until April 19, 2015 and then move to a church in Hamburg, Germany. (Photo by Ronald Zak/AP Photo)

A mother takes a selfie while breastfeeding her baby at the “Hakab Na 2018”, an event held in celebration of National Breastfeeding Awareness Month at the SMX Convention Center in Pasay City, Philippines on Sunday, August 5, 2018. Now on its sixth year, the event is a gathering of families, lactation experts, peer counselors and breastfeeding advocacy supporters and was aimed at promoting the importance of providing support to breastfeeding mothers. (Photo by Avito C. Dalan/PNA Photo)

People look at a loaded truck that got stuck in a sinkhole on a road in Guilin, Guangxi Zhuang Autonomous Region, January 7, 2015. No injury was reported, according to local media. (Photo by Reuters/Stringer)

A woman plays around as she walks across a glass-bottomed suspension bridge in a scenic zone in Pingjiang county in southern China's Hunan province Thursday, September 24, 2015. The bridge, 300 meters (984 feet) long and 180 meters (590 feet), opened to visitors on Thursday for the first time since its conversion from a regular suspension bridge was completed. (Photo by Chinatopix Via AP Photo)