Yang Shiguang, 77, performs stunts at a park in Xi'an, Shaanxi province, September 3, 2013. Yang has been a member of a stunt performance club since 2007, after retiring from a research institution. (Photo by Reuters/China Daily)

Christian people crowd a bush taxi on a road 55km north of Bangui as they are on their way to the capital where they expect to sell some products on the market on January 19, 2014. Fresh fighting broke out in the strife-torn Central African Republic on the eve of an announcement on Sunday of the candidates seeking to become the new interim president. Sectarian violence has gripped the landlocked country after a March 2013 coup launched by the mostly Muslim Seleka rebels, and the UN has warned that the bloodshed could turn into genocide. (Photo by Eric Feferberg/AFP Photo)

(L-R) Maria Silva, Milena Cortes, Maria Arteaga, Jackeline Bastidas and Gissy Abello pose for a picture at the Famproa dogs shelter where they work, in Los Teques, Venezuela, August 25, 2016. Venezuelans struggling to feed their families let alone their pets are dumping animals on the streets, in parks and at makeshift homes overrun with scrawny animals amid an economic crisis. An hour from Caracas in Los Teques, hundreds of dogs bark and run around the streets scavenging for food outside a makeshift shelter. (Photo by Carlos Garcia Rawlins/Reuters)

This picture taken on July 15, 2014 shows a bridge submerged in floodwaters in the ancient town of Fenghuang, central China's Hunan province. Rainstorms lashed central China's Hunan Province and southwest China's Guizhou Province, affecting over 1 million people and flooding a historical town, state media reported. (Photo by AFP Photo)

Joshua Patino stands on a ladder to put finishing touches on a giant dinosaur exhibit at PAX East in the Boston Convention and Expo Center, Thursday, April 21, 2016, in Boston. PAX East, an annual celebration of gaming culture, is expected to draw tens of thousands of visitors Friday through Sunday. It's a place where serious gamers can preview unreleased video games and devices, compete in tournaments, hear live music and meet others for whom gaming is a way of life. (Photo by Elise Amendola/AP Photo)

Gardener Peter Glazebrook poses for photographers with his world record breaking onion at The Harrogate Autumn Flower Show on September 16, 2011 in Harrogate, England. Peter Glazebrook from Newark, Nottinghamshire claimed a Guinness World Record with his giant onion weighing 8.150 kg. (Photo by Christopher Furlong/Getty Images)

This artist's scoreboard displays a fictional game between Mars and Earth, with Mars in the lead. It refers to the success rate of sending missions to Mars, both as orbiters and landers. Of the previous 39 missions targeted for Mars from around the world, 15 have been successes and 24 failures. For baseball fans, that's a batting average of .385. The United States has had 13 successes out of 18 attempts, or a “batting average” of .722. NASA's Curiosity rover, set to land on the Red Planet the evening of Aug. 5, 2012 PDT (morning of Aug. 6 EDT), will mark the United States' 19th attempt to tackle the challenge of Mars, and the world's 40th attempt. (Image by NASA/JPL-Caltech)

Festivalgoers watch two actors of the Wasteland Warriors movement fight in a cage at the world's largest heavy metal festival, the Wacken Open Air 2019, in Wacken, Germany on August 3, 2019. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Wolfgang Rattay/Reuters)