Colorado Gov. John Hickenlooper shows off his socks--one with Democratic presidential candidate Bernie Sanders and the other with Republican candidate Donald Trump – before entering his former brewpub for a book signing event to mark the release of his autobiography Thursday, May 26, 2016, in Denver. Hickenlooper, who is term-limited, is doing book talk rounds this week, reviving speculation that he is positioning himself to join Hillary Clinton's presidential campaign ticket. (Photo by David Zalubowski/AP Photo)

At 10,582 square kilometres, the Bolivian salt flats – otherwise known as Salar de Uyuni – are the largest on the planet and contain between 50 and 70% of the world’s lithium reserves. After exploring Chile and Argentina, photographer Joel Santos decided to travel to Bolivia in January 2017 to check the salt flats off his bucket list. With an electrical storm rolling in, Joel and his two travelling companions were the only souls left on the vast flats and captured the eerie flats without a person in sight. (Photo by Joel Santos/Barcroft Images)

Danielle Collins of the US reacts to a point in the first set while playing Caroline Wozniacki of Denmark during Round Two Women's Singles tennis match of the 2019 US Open at the USTA Billie Jean King National Tennis Center in New York on August 29, 2019. (Photo by Robert Deutsch/USA TODAY Sports)

Fatima Rezai, 21, a female officer from the Afghan National Army (ANA) practices with a punch bag during an exercise session at at the Kabul Military Training Centre (KMTC) in Kabul, Afghanistan October 23, 2016. (Photo by Mohammad Ismail/Reuters)

Model Kendall Jenner poses on the red carpet as she arrives for the screening of the film “Mal de pierres” (From the Land of the Moon) in competition at the 69th Cannes Film Festival in Cannes, France, May 15, 2016. (Photo by Yves Herman/Reuters)

Model Ming Xi falls as she presents a creation during the 2017 Victoria's Secret Fashion Show in Shanghai, China, November 20, 2017. (Photo by David Fisher/Rex Features/Shutterstock)

Singer Halsey arrives to the 2018 amfAR Gala New York at Cipriani Wall Street on February 7, 2018 in New York City, USA. (Photo by Splash News and Pictures)

A dog sits in a plastic tub filled with water in Taipei, Taiwan, 28 July 2020. Betel nut seller Mr Luo, the dog's owner, said he puts his dog, a 12-year-old mixed breed called Ah Dai (Stupid), in a plastic tub filled with water whenever the weather gets hot. Ah Dai enjoys the bath and can sit in the basin for hours, according to Mr Luo. Luo has a dozen pairs of glasses for Ah Dai, so the dog wears different glasses every day and many tourists take photos of Ah Dai. (Photo by David Chang/EPA/EFE)