Cheerleaders let their hair fly as they perform prior to a German first division Bundesliga soccer match between 1. FC Cologne and Bayern Munich in Cologne, Germany, March 4, 2017. (Photo by Michael Probst/AP Photo)

Almost two years old male baby orang-utan Dalai looks on in the zoo in Dresden, Germany, 30 March 2017. Dalai was born to mother Daisy in June 2016. (Photo by Filip Singer/EPA)

An Israeli soldier looks through her cell phone as she enjoys the Ranunculus flowers in a field in the southern Israeli Kibbutz of Nir Yitzhak, located along the Israeli- Gaza Strip border, during the Jewish holiday of Pesach (Passover) on April 12, 2017. (Photo by Menahem Kahana/AFP Photo)

A four-day old African spurred tortoise, Geochelone sulcata, one of eight babies, was place on the head of its mother in their enclosure in Nyiregyhaza Animal Park in Nyiregyhaza, 226 km east of Budapest, Hungary, 27 September 2011. This was the first time that offspring of an African spurred tortoise were born in this zoo. The eight babies hatched after 115 days, they are 5.5 cms long and weigh 25 grams. Spurred tortoise is the largest species of land tortoises in Africa, the weight of an adult animal may reach 80 kgs. (Photo by Attila Balazs/EPA)

A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 on March 1, 2011. (Photo by Tech. Sgt. Manuel J. Martinez/U.S. Air Force)

Britain's Princess Elizabeth clasps her hands in sympathy as Sergeant Jean Bayliss faints at her feet during an inspection of the guard of honour of the Women's Royal Army Corps at Shrewsbury Castle, Shropshire, on July 6, 1949. (Photo by AP Photo)

Seljalandsfoss waterfall, located in Iceland. Seljalandsfoss is one of the most famous waterfalls of Iceland. This waterfall of the river Seljalandsá drops 60 metres (200 ft) over the cliffs of the former coastline. It's possible to go behind the waterfall. (Photo by HotSpot Media)

Boeing B-29 (#10) from the 24th Bomb Squadron, 6th Bomb Group after an emergency landing at Iwo Jima on April 24,1945. (Photo by U.S. Air Force)