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 robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

Laura Paipo (L), first blind principal in Uruguay participates in a street race with her sighted guide and friend Amparo Bauter in Montevideo, October 4, 2015. Paipo, 55, who took office on August 10, 2015 became the first blind principal of a special school which specializes in the education of visually impaired students. (Photo by Andres Stapff/Reuters)

A swan is carried down the nave of the cathedral during the Procession of the Animals at the 31st annual Feast of Saint Francis and Blessing of the Animals at The Cathedral of St. John the Divine in the Manhattan borough of New York on October 4, 2015. (Photo by Elizabeth Shafiroff/Reuters)

Audrey Mata from Washington D.C in the U.S. dressed as Princess Leia, comes face to face with a replica of R2-D2 at the 'For The Love of The Force' Star Wars fan convention in Manchester, northern England, December 4, 2015. (Photo by Phil Noble/Reuters)

A Hindu holy man or Sadhu walks back to his ashram after taking a dip at Sangam, confluence of Ganges river, Yamuna river and mythical Saraswati river in Allahabad, India, Thursday, August 4, 2016. (Photo by Rajesh Kumar Singh/AP Photo)

Vatican Swiss Guards stand attention at the St. Damaso courtyard on the occasion of the swearing-in ceremony at the Vatican, Sunday, October 4, 2020. The ceremony is held to commemorate the day in 1527 when 147 Swiss Guards died protecting Pope Clement VII during the Sack of Rome. (Photo by Gregorio Borgia/AP Photo)

Buddy Mae Walker (R), 4, looks at herself in the mirror while trying on a child respirator provided by the non-profit TeamRaccoonPDX on October 6, 2020 in Portland, Oregon. We told them their grandparents sent them space suits to keep them safe, Jessica Walker said of the respirators, which the family sought out after police used tear gas near their residential street. (Photo by Nathan Howard/Getty Images)