A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)

One of the most significant challenges related to cancer in Nepal is the lack of awareness around the prognosis of the disease, as many patients, their families and even healthcare professionals consider cancer to be an incurable disease at any stage. This results in significant delays in bringing patients to hospitals, and high rates of advanced stage cancers and mortality. (Photo by Omar Havana)

1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

A cat and a seagull feeding on a street in Heybeliada, the second largest of the Prince Islands in the Sea of Marmara, near Istanbul, Turkey on February 01, 2017. (Photo by Sebnem Coskun/Anadolu Agency/Getty Images)

Snow covered mountains are seen from the waters of Unstad along the northern Atlantic Ocean on March 12, 2017, where the water temperatures is at five degrees centigrade and the air temperature is at minus two degrees centigrade. Unstad, the world' s most northern surf school, is perfect for those wanting to experience Arctic Surfing. (Photo by Olivier Morin/AFP Photo)

A leaf from a sweetgum tree (Liquidambar styraciflua) lies on the grass at Godewaersvelde early October 27, 2017. (Photo by Philippe Huguen/AFP Photo)

Anna Malova, Miss Russia 1998, poses on a pool table at The Campbell Apartment restaurant in Grand Central Station on November 18, 1999. She makes her motion picture debut in the movie “Above Ground”. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)