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 monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

A man holds a cow at the cattle market in Maiduguri, Nigeria, March 9, 2016. A Nigerian government push to strangle the Boko Haram insurgency has shut down the cattle trade that sustained the city of Maiduguri, leaving many residents with no livelihood, including many of the two million people displaced by the war. In recent months the army has taken back much of the territory lost to the jihadists during the five-year insurgency. (Photo by Afolabi Sotunde/Reuters)

Rohingya refugee children pictured in a camp in Cox's Bazar, Bangladesh, September 19, 2017. With a mass exodus of Rohingya Muslims sparking accusations of ethnic cleansing from the United Nations and others, Myanmar leader Aung San Suu Kyi on Tuesday said her country does not fear international scrutiny and invited diplomats to see some areas for themselves. (Photo by Cathal McNaughton/Reuters)

Richard Coleby of Polaris falls over his quad into muddy waters during day one of the HydroGarden Weston Beach Race on October 14, 2017 in Weston-Super-Mare, England. (Photo by Michael Steele/Getty Images)

Eagle Prime (MK3), a giant robot by MegaBots Inc. which manufactures giant piloted humanoid fighting robots headquartered in Berkeley, California on October 18, 2017. (Photo by Courtesy Michael Mauldin/Reuters/MegaBots Inc)

People carrying torches march during the traditional Bonfire Celebrations in Lewes, Britain on November 4, 2017. Lewes holds Britain's largest Bonfire night celebrations. The event marks Guy Fawkes Night and the uncovering of the Gunpowder Plot in 1605 and commemorates the memory seventeen Protestant martyrs from the town who were burned at the stake. Thousands gather with flaming torches to march through the street and burn effigies. (Photo by Neil Hall/EPA/EFE)

A girl dressed up as a emissary of the Three Wise Men poses for a photo as she waits for their arrival in a helicopter to take part in the traditional Epiphany parade in Ronda, Spain, January 5, 2018. (Photo by Jon Nazca/Reuters)