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)

Chicken, fish and eggs lie next to coca paste worth $14,000 Colombian pesos at a local store in Guyabero Region, Guaviare, Colombia, May 24, 2016. As the government nears a historic peace deal with the rebels of the Revolutionary Armed Forces of Colombia (FARC), the nation's authorities are struggling to tame an increase in farming of coca, the raw material used to make cocaine. In the Guyabero Region, where many people work on coca plantations, locals barter coca paste to buy groceries at the local shop. (Photo by John Vizcaino/Reuters)

Pfc. Esmeralda Calderon stands and salutes the flag on the 15th green during the first round of the LPGA golf tournament at Kingsmill Resort and Golf Course in Williamsburg, Va., Thursday May 23, 2019. Pfc. Calderon, from San Antonio, Texas, is a Marine assigned to Naval Weapons Station Yorktown. (Photo by John Sudbrink/The Daily Press via AP Photo)

Kindergartner Cameron McManus, 5, watches as a fellow student has his portrait made during “picture day” at Rogers International School on September 23, 2020 in Stamford, Connecticut. Students lined up outside to be photographed while socially distanced due to COVID-19 precautions. Most students at Stamford Public Schools are taking part in a hybrid education model, attending in-school classes every other day and distance learning the rest. (Photo by John Moore/Getty Images)

A protestor confronts police and National Guard troops near the Wauwatosa City Hal on October 09, 2020 in Wauwatosa, Wisconsin. The city has faced three days of demonstrations, prompting a 7 PM curfew, after District Attorney John Chisholm refused to press charges against Wauwatosa Police Officer Joseph Mensah for the Feb. 2 fatal shooting of 17-year-old Alvin Cole. (Photo by Scott Olson/Getty Images)

Police officers look on as protesters block the road with burning tyres and wood, during a mass protest the morning after preliminary results were released for five communes in Conakry on October 21, 2020. African monitors said on October 20, 2020, that Guinea's weekend election was conducted properly, but the political opposition to incumbent Alpha Conde, which has already claimed victory, dismissed it as fraudulent. (Photo by John Wessels/AFP Photo)

Staff members work on sorting and assembling the skeleton of a fossilized Triceratops dinosaur, in Paris, France, 31 August 2021. The skeleton of a Triceratops, an over 66 million years old dinosaur, knicknamed “Big John”, will be auctioned at the Drouot Auction House on 21 October 2021 and is estimated to fetch a total of 1.5 million euros. (Photo by Christophe Petit Tesson/EPA/EFE)

Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)