A zoo performer smiles as he puts his head between the jaws of a crocodile during a performance for tourists at the Sriracha Tiger Zoo, in Chonburi province, east of Bangkok,Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. (Photo by Kenshin Okubo/AP Photo/The Daily Free Press)

P.S. All pictures are presented in high resolution.

Turkana tribesmen walk with guns to protect their cattle from rival tribes near Baragoy, Kenya August 4, 2017. (Photo by Goran Tomasevic/Reuters)

A priest is seen looking out of Abuna Yemata church’s only window. Priests cheerfully tell visitors that pregnant women, babies and old people attend Sunday services and no one has fallen off. (Photo by Ethiopia – The Living Churches of an Ancient Kingdom/The American University in Cairo Press/The Guardian)

1st Place in Wildlife: A male orangutan peers from behind a tree while crossing a river in Borneo, Indonesia. (Photo by Jayaprakash Joghee Bojan/National Geographic Nature Photographer of the Year contest 2017)

An Afghan street vendor carries bread on his head ahead of the upcoming holy fasting month of Ramadan in Kabul, Afghanistan, Sunday, June 5, 2016. Muslims across the world will be observing the holy fasting month of Ramadan, when they refrain from eating, drinking and smoking from dawn to dusk. (Photo by Rahmat Gul/AP Photo)