Mariam, a 9-year-old girl, carries her brother as she stands with other children at an underground ancient cemetery in Jabal al-Zawiya in the southern countryside of Idlib November 26, 2014. Residents are using ancient caves and cemeteries as underground shelters to hide in during shelling from forces loyal to President Bashar al-Assad. Picture taken November 26, 2014. (Photo by Khalil Ashawi/Reuters)

A breeder poses with fruits and specially made high-fibre bread, for 36-year-old giant panda Jia Jia, at the Hong Kong Ocean Park, China June 30, 2015. Jia Jia, the oldest giant panda living in captivity, is set to challenge the world record for the animals' longevity, with her age said to put her on par with a human centenarian. (Photo by Tyrone Siu/Reuters)

A customer shops at an Alibaba rural service centre in Jinjia Village, Tonglu, Zhejiang province, China, July 20, 2015. E-commerce growth in the countryside now outpaces that in major cities, though fewer than one tenth of online purchases made on Alibaba platforms were shipped to rural areas in the first quarter of this year. Alibaba estimates the potential market at 460 billion yuan ($74 billion) by next year. (Photo by Aly Song/Reuters)

Yalena Leuliette, 7, of Greenbelt, Md., throws seeds from a cattail plant up in the air as she plays while visiting the Kenilworth Aquatic Gardens in northeast Washington, on Sunday, August 9, 2015. Leuliette visits the public garden with her parents a few times a year. (Photo by Jacquelyn Martin/AP Photo)

Scarlett points at the huge ice sculpture of a bear during a Photocall for Magical Ice Kingdom at Hyde Park Winter Wonderland at Hyde Park on November 17, 2016 in London, England. It is the event's 10th anniversary this year. (Photo by Ben Perry/Getty Images)

A woman dressed for la “La Diablada” festival, walks down a road in Pillaro, Ecuador, Friday, January 6, 2017. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Afghan children play on the remains of a Soviet-era armored personnel carrier on the outskirts of Jalalabad on February 15, 2016. Soviet troops withdrew from Afghanistan on February 15, 1989, after ten years of fighting against Mujahidin militiamen. (Photo by Noorullah Shirzada/AFP Photo)

A picture shows the full moon during a “blood moon” eclipse over the temple of Apollo in Corinth on July 27, 2018. The longest “blood moon” eclipse this century began on July 27, coinciding with Mars' closest approach in 15 years to treat skygazers across the globe to a thrilling celestial spectacle. (Photo by Valerie Gache/AFP Photo)