Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

Two novice Buddhist monks walk alongside a basket seller to collect alms following a clerics rule of no footwear nor use of umbrellas in Mandalay, Myanmar, Friday, October 9, 2015. (Photo by Hkun Lat/AP Photo)

An elephant “kisses” a visitor during a show at an elephant training school in Xishuangbanna, Yunnan province, April 18, 2015. Some 16 elephants live at the school and give four 30-minute performances everyday for visitors. (Photo by Wong Campion/Reuters)

Miss Brazil Julia Gama reacts after her team won the tug of war event during the Miss World sports competition at the Lee Valley sports complex in north London, November 26, 2014. Contestants from 126 countries are in London to compete in the 2014 Miss World competition. (Photo by Andrew Winning/Reuters)

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

Filipino Muslims ride on top of a vehicle as they celebrate the end of the holy month of Ramadan in Cotabato city, in southern Philippines, July 16, 2015. Picture taken July 16, 2015. (Photo by Marconi Navales/Reuters)

Nine year old girl Barsati reacts while walking on a tightrope in Mumbai on February 11, 2014. Barsati, and her younger brother Rajababu, (4) earn an average of around 2000 rupees (32 dollars) per day from pedestrians and tourists performing various acts on the tightrope near the city's iconic landmark Gateway of India. (Photo by Indranil Mukherjee/AFP Photo)

This image provided by NASA shows parts of Europe and Africa very easily recognizable in this night time image shot by one of the Expedition 25 crew members aboard the International Space Station flying 220 miles above Earth on Thursday October 28, 2010. The view “looks” northward over Sicily and the “boot” of Italy, with the Mediterranean Sea representing most of the visible water in the view and the Adriatic Sea to the right of center. Tunisia is partially visible at left. Part of a docked Russian spacecraft and other components of the ISS are in the foreground. (Photo by AP Photo/NASA)