A Sadhu, or a Hindu holy man, performs yoga on International Yoga Day at Kamakhya temple in Guwahati, India on June 21, 2018. (Photo by Anuwar Hazarika/Reuters)

A woman watches the rain from inside a stranded vehicle on a flooded street in Mianyang, Sichuan, China on July 11, 2018. (Photo by China News Service via Reuters)

A girl walks along former railway tracks in the so- called “Tunnel of Love”, surrounded by arches of intertwined trees, near the Ukrainian village of Klevan, Rivno region, on August 6, 2018. The tunnel of about five kilometres in length is a botanical phenomenon, which became a cult place for tourists and couples in love. The tourist legend says that wishes of couples in love will come true, if the couple passes through the tunnel. (Photo by Sergei Supinsky/AFP Photo)

Hooded demonstrators vandalise a shop window in Mexico City, during the commemoration of the 50th anniversary of the 1968 Tlatelolco student massacre, on October 2, 2018. Fifty years ago, Mexican troops opened fire on student demonstrators, killing hundreds just days before Mexico City hosted the 1968 Olympics – one of the darkest episodes in a year of global turbulence. (Photo by Ronaldo Schemidt/AFP Photo)

Nguyen Thi Vui paddles her boat in the flooded streets of Hoi An, Vietnam, Monday, November 6, 2017. A powerful typhoon that rocked Vietnam has killed dozens of people and caused extensive damage to the country's south-central region ahead of the APEC summit that will draw leaders from around the world, the government said Monday. (Photo by Hau Dinh/AP Photo)

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 participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)

London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/Reuters)