Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

This photo released Saturday March 22, 2014 by Stichting Ambulance Wens or Ambulance Wish Foundation shows a giraffe at Blijdorp Zoo in Rotterdam giving a lick to terminally ill Mario Eijs on Wednesday March 19, 2014. The Stichting Ambulancewens “Ambulance Wish Foundation” offers transport for terminally ill patients who cannot walk to help fulfill a last wish, in Eijs' case to be taken to the Blijdorp Zoo in Rotterdam where he worked doing odd jobs for 25 years. Eijs, who has a mental handicap, is dying of a brain tumor and has difficulty walking or speaking. (Photo by AP Photo/Stichting Ambulance Wens)

A firefighter holds a red panda (Ailurus fulgens) from its tail while removing it from a tree at a residential area in Kunming, Yunnan province, July 3, 2014. The animal was spotted in the residential area and was brought down from the tree after residents reported its sighting to the police, local media reported. (Photo by Reuters/Stringer)

These two young siblings appear to cling on to a tree for dear life and even hold hands as they learn the ropes of climbing, on June 25, 2013. (Photo by Tim Fitzharris/Minden/Solent)

A staff member sets up a ROBOTLEO robot at the Global Mobile Internet Conference (GMIC) 2017 in Beijing, China April 28, 2017. (Photo by Jason Lee/Reuters)

Paramilitary policemen carry seized crystal meth at Boshe village, Lufeng, Guangdong province, December 29, 2013. Police in the southern Chinese province of Guangdong have seized nearly three tonnes of the drug crystal methamphetamine and arrested 182 people in raids on a village notorious for producing narcotics. (Photo by Reuters/Stringer)

In this image distributed on Tuesday, September 29, 2015, 11-year old dance star Taylor Hatala and friends are seen filming their new Monster High Boo York, Boo York music video #CityGhouls in Los Angeles. (Photo by Casey Rodgers/Invision for Mattel/AP Images)

Ethnic Uyghur tourists guides wait to perform in a show for Chinese tourists on June 29, 2017 in the old town of Kashgar, in the far western Xinjiang province, China. Kashgar has long been considered the cultural heart of Xinjiang for the province's nearly 10 million Muslim Uyghurs. (Photo by Kevin Frayer/Getty Images)