A Chinese People's Liberation Army soldier marches with members of an honor guard as they prepare for a welcome ceremony for visiting Luxembourg's Prime Minister Xavier Bettel outside the Great Hall of the People in Beijing, Monday, June 12, 2017. (Photo by Andy Wong/AP Photo)

Somali couple Mohamed Noor (L) and Huda Omar pose for a photograph at their makeshift home during their wedding ceremony in Mogadishu's Rajo camp, Somalia August 17, 2016. Having met two years ago, the pair have just married at Rajo camp, where some 400 families live. Most, like Noor's parents, came here in the early 1990s to flee famine. (Photo by Feisal Omar/Reuters)

A group of fashionable nonagenarians pose for a photo in Pengzhou, Sichuan, China on October 12, 2016. (Photo by Rex Features/Shutterstock)

People out in Aberystwyth on “Booze Black Friday” or “Mad Friday” in Aberystwyth, Wales, UK on December 16, 2016. The “Booze Black Friday” is the last working Friday before Christmas when workers celebrate with their colleagues. Alcohol sales in pubs, clubs and off-licences rise dramatically on this day. (Photo by Keith Morris/Alamy Live News)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

People pause at a memorial set up for victims of a mass shooting in Las Vegas, Nev., on Tuesday, October 3, 2017. A gunman opened fire on an outdoor music concert on Sunday. It was the deadliest mass shooting in modern U.S. history, with dozens of people killed and hundreds injured, some by gunfire, some during the chaotic escape. (Photo by John Locher/AP Photo)

A cat tries to find dry ground around an apartment complex in Houston after Hurricane Harvey hit on Aug. 30. Harvey made landfall in South Texas on August 25, leading to days of downpours that dumped more than 50 inches of rain. Harvey damaged or destroyed about 200,000 homes as the storm system flooded much of Houston and smaller coastal communities. (Photo by Scott Olson/Getty Images)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. (Photo by Mario Tama/Getty Images)