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)

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)

An Indian man, Kalpesh Modi, performs stunts with his motorcycle during the rehearsal for the forthcoming Lord Jagannath Rath Yatra, an annual Hindi festival, in Ahmedabad on June 23, 2019. The 142nd Lord Jagannath Rath Yatra festival in Ahmedabad is scheduled for July 4. (Photo by Sam Panthaky/AFP Photo)

Over 30 Douglas C-47 Skytrains (Dakotas) making final preparations for flight formation practice before the 75th D-Day Anniversary flight to Normandy in Duxford, England on June 4, 2019. (Photo by UK Air Force Images)

Bus ushers leap as they pose for a group photo during a meeting one day ahead of the opening session of China's National People's Congress (NPC) at the Great Hall of the People in Beijing, Monday, March 4, 2019. (Photo by Mark Schiefelbein/AP Photo)

A Hindu holy man with his face smears with ash and vermilion powder adjusts his head gear sitting at the courtyard of the Pashupatinath Temple during Shivaratri festival in Kathmandu, Nepal, Monday, March 4, 2019. Shivaratri, or the night of Shiva, is dedicated to the worship of Lord Shiva, the Hindu god of death and destruction. (Photo by Niranjan Shrestha/AP Photo)

British model Demi Rose, 24, showed off her curves in a photo shoot in Tunisia on Saturday, May 4, 2019. The Birmingham-born beauty slipped into a nude two-piece dripping in jewels and went barefoot the photo shoot in a temple. (Photo by KP Pictures)