Jennifer Oeser of Germany competes in the Women's Heptathlon Long Jump on Day 8 of the Rio 2016 Olympic Games at the Olympic Stadium on August 13, 2016 in Rio de Janeiro, Brazil. (Photo by Alexander Hassenstein/Getty Images)

Ten-year-old Macy Friday, front left, reacts as she looks back at her family after meeting Hillary Clinton, front right, as she campaigns for U.S. Sen. Mark Udall, D-Colo., back, during a stop in the newly-renovated Union Station in Denver on Monday, October 13, 2014. Clinton appeared at an event to raise money for Udall's current re-election campaign and then headed to Las Vegas for another appearance on Monday night. (Photo by David Zalubowski/AP Photo)

A woman offers prayers by a road as a rickshaw puller transports passengers in Kolkata October 28, 2014. (Photo by Rupak De Chowdhuri/Reuters)

Sheep are herded during the annual sheep parade through Madrid November 2, 2014. Shepherds parade the sheep through the city every year in order to exercise their right to use traditional routes to migrate their livestock from northern Spain to winter grazing pasture land in southern Spain. (Photo by Susana Vera/Reuters)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

A child uses an umbrella to avoid rain falling on a fire at the northern Greek border point of Idomeni, Greece, Monday, April 25, 2016. Many thousands of migrants remain at the Greek border with Macedonia, hoping that the border crossing will reopen, allowing them to move north into central Europe. (Photo by Gregorio Borgia/AP Photo)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)

Iraqis run for cover as they flee Mosul's Al-Tayaran neighbourhood on February 28, 2017, during an offensive by Iraqi forces to retake the area from Islamic State (IS) group fighters. Hundreds of civilians fled through the desert to escape fighting and privation in Mosul, joining thousands of others who left their homes as conditions worsen in the city's west. (Photo by Ahmad Al-Rubaye/AFP Photo)