Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

A soldier from the South Korean army special forces breaks stone plates with her head during a martial arts demonstration for Memorial Day at Korea War Memorial Museum in Seoul, South Korea, Monday, June 6, 2016.(Photo by Ahn Young-joon/AP Photo)

A Hindu devotee performs a stunt with fire during a rehearsal for the annual Rath Yatra, or chariot procession, which commemorates a journey by Hindu god Jagannath, his brother Balabhadra and sister Subhadra, in specially made chariots, in Ahmedabad, India, June 26, 2016. (Photo by Amit Dave/Reuters)

A woman greets a street artist at the San Fermin festival in Pamplona, northern Spain July 8, 2016. (Photo by Eloy Alonso/Reuters)

Young revelers take part in a parade called "La Calabiuza" on November 1, 2015, on the eve of the Day of the Dead in Tonacatepeque, 20 kms (13 miles) north of San Salvador. During the celebration, the residents of Tonacatepeque, originally an indigenous community, recall the characters from the mythology of Cuscatlan – pre-Columbian west and central regions of El Salvador – and their dead relatives. (Photo by Marvin Recinos/AFP Photo)

A group of men play Myanmar's traditional sport of chinlone in Naypyitaw, Myanmar, Friday, November 18, 2016. (Photo by Aung Shine Oo/AP Photo)

A Kashmiri villager shouts freedom slogans during the funeral procession of Asadullaha Kumar in Mandhaal village, some 70 Kilometers south of Srinagar, Indian controlled Kashmir, Saturday, December 3, 2016. Hundreds of angry villagers blocked the Srinagar-Jammu highway for hours alleging Kumar was tortured and then shot by Indian forces while he was performing his duty as a security guard at a government fishery. Police officers denied the allegation and said he was killed in cross-firing during an overnight counter-insurgency operation in south Kashmir. (Photo by Dar Yasin/AP Photo)

A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)