People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)

World Champion Trials bike rider Jack Field of Australia poses after performing the highest backflip on a motorcycle ever recorded as he flips his motorbike upside down on the roof of Melbourne's Eureka Tower (297.3 metres) during a AUS-X Open media opportunity at Eureka Tower on May 22, 2019 in Melbourne, Australia. The largest international Supercross and action sports event in the world outside of the USA, the AUS-X Open will be held at Melbourne's Marvel Stadium on November 30 2019. (Photo by Scott Barbour/Getty Images)

Russia's Dina Averina competes in the ball event of the rhythmic gymnastics individual final at the 2019 European Games in Minsk on June 23, 2019. (Photo by Kirill Kudryavtsev/AFP Photo)

A child covered in mud on Lake Chokrak near the village of Kurortnoye, Leninsky District of Crimea in Russia on July 4, 2019. (Photo by Sergei Malgavko/TASS)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)

Fans of the Brazilian heavy metal band Sepultura enjoy their showo at the main stage of Rock in Rio festival 2019 at the Olympic Park, Rio de Janeiro, Brazil, on October 4, 2019. The week-long Rock in Rio festival started September 27, with international stars as headliners, over 700,000 spectators and social actions including the preservation of the Amazon. (Photo by Mauro Pimentel/AFP Photo)

In this Thursday, October 3, 2019 photo, a female black bear sleeps with its tongue out high up in a Ponderosa pine tree near Clark Fork School in the Rattlesnake neighborhood of Missoula, Mont. The bear's cub, not pictured, was snoozing on a nearby branch. (Photo by Tommy Martino/The Missoulian via AP Photo)

Syrians gather during an evacuation operation of rebel fighters and their families from rebel-held neighbourhoods on December 15, 2016 in the embattled city of Aleppo. A convoy of ambulances and buses left rebel territory in Aleppo in the first evacuations under a deal for opposition fighters to leave the city after years of fighting. The rebel withdrawal will pave the way for President Bashar al-Assad's forces to reclaim complete control of Syria's second city, handing the regime its biggest victory in more than five years of civil war. (Photo by Karam Al-Masri/AFP Photo)