Frances Fowler leads the Bowie VFD Marching Thoroughbreds in the Bowie 4th of July Parade in Bowie, Md., on July 4, 1976. (Photo by James M. Thresher/The Washington Post via Getty Images)

A Philippine boy collects used plastic bottles to be sold at a junk shop at Divisoria market in Manila on November 29, 2017. (Photo by Noel Celis/AFP Photo)

Margaret Morris dancers exercising on the sands at Saint-Idesbald. (Photo by Fox Photos/Getty Images). August 1929

A villager pours brine into troughs at ancient salt fields on May 5, 2005 in Yantian Village on Hainan Island, China. (Photo by China Photos/Getty Images)

Photographer Loes Heerink spent hours waiting on bridges in Hanoi to capture the street vendors who walked underneath. She recently launched a Kickstarter project to publish a book of these images. Here: “In Hanoi there are a lot of street vendors who roam the city with their bicycles trying to sell goods, from vegetables to flowers”. (Photo by Loes Heerink/The Guardian)

Moonlight illuminates sandstone buttes in the Valley of the Gods in the proposed Bear Ears National Monument near Mexican Hat, Utah, USA, 12 November 2016. In October 2015, a coalition of five Indian nations, including the Hopi, Ute, and Navajo, formally proposed the monument, attempting to preserve the parcel's 100,000 archeological sites from ongoing looting and grave robbing. Less than two months before handing over the White House to President Elect Trump, President Obama must decide if it's worth the political capital to designate Bear Ears a national monument. (Photo by Jim Lo Scalzo/EPA)

Record snowfall in the Sahara Desert near the town of Ain Sefra in Algeria on January 21, 2017. (Photo by Geoff Robinson/Rex Features/Shutterstock)

Baka pygmies in their forest home preparing food in, Sangha Forest, Central African Republic, February 2016. Here, in their forest home, traditional life continues in the face of multiplying challenges ranging from poachers, to ill health. Deep in the rainforests of central Africa lives one of the world’s most mysterious tribes. (Photo by Susan Schulman/Barcroft Images)