Riot policemen launch tears gas canisters during clashes with coca growers from Yungas in La Paz, Bolivia February 21, 2017. (Photo by David Mercado/Reuters)
View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)
A couple dressed as clowns stands near the beach during the Carnival Clown's Parade at Sesimbra village, Portugal on February 27, 2017. (Photo by Patricia De Melo Moreira/AFP Photo)
A dancer prays before she performs as land activists gather to commemorate the upcoming Women's Day in Phnom Penh, Cambodia, March 7, 2017. (Photo by Samrang Pring/Reuters)
A young woman employee of North American Aviation Incorporated, working over the landing gear mechanism of a P-51 fighter plane, Inglewood, California, 1942. (Photo by Alfred T. Palmer/Buyenlarge/Getty Images)
Models of the SibPlus Models agency and participants of the Miss Doughnut beauty competition take part in a rehearsal in Krasnoyarsk, Siberia, Russia, March 4, 2017. (Photo by Ilya Naymushin/Reuters)
In this Sunday, March 5, 2017, photo, hospitality staff take souvenir photos in front of the Great Hall of the People where the National People's Congress is held in Beijing. (Photo by Andy Wong/AP Photo)
An Orchid Mantis (Hymenopus coronatus) is perched on the head of a frog hanging from a tree branch on March 15, 2017 in Padang, Indonesia. (Photo by Riau Images/Barcroft Images)