Iraqi troops fire artillery towards Islamic State (IS) group jihadists' positions in west Mosul on March 11, 2017 during the ongoing battle to retake the city from the group. (Photo by Aris Messinis/AFP Photo)

Fans are seen at the 143rd Kentucky Derby on May 6, 2017 in Louisville, Kentucky. (Photo by Michael Hickey/Getty Images)

Skiers and snow boarders descend from a slope as they attempt to break the record for mass skiing in swimming suits at Rosa Khutor resort near Sochi, Russia, April 9, 2016. (Photo by Kazbek Basayev/Reuters)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

Azat Shajbyrov reacts with a baby falcon on his head in a village of Bokonbaevo, Issyk-Kul area (270 km from Bishkek), Kyrgyzstan, 22 June 2016, as he dreams of continuing a family tradition of golden eagle hunting. Eagle and falcon hunting is an old Kyrgyz tradition. With their birds, Kyrgyz berkutchy hunt in the mountains and participate in the hunting festival “Salburun”. (Photo by Igor Kovalenko/EPA)

Children ride in the trunk of a car on a flooded street in Sanaa, Yemen August 1, 2016. (Photo by Khaled Abdullah/Reuters)

Two race pigs jump over an obstacle during a rural festivity in reference to Maria Ascension in San Bernardino, Switzerland on Monday, August 15 2016. (Photo by Samuel Golay/Keystone/TI-Press via AP Photo)

Toyoda Gosei Co Ltd's personal mobility concept airbag car "Flesby" is displayed at the 44th Tokyo Motor Show in Tokyo, Japan, October 28, 2015. (Photo by Yuya Shino/Reuters)