A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

A female Chinese People's Liberation Army soldier looks at members of an honor guard preparing for a welcome ceremony for visiting German President Joachim Gauck, outside the Great Hall of the People in Beijing, Monday, March 21, 2016. (Photo by Andy Wong/AP Photo)

Models take part in the promotion of the Miss Bumbum (buttocks) beauty pageant, along Paulista Avenue in Sao Paulo, Brazil, on August 7, 2017. The annual Bumbum pageant to select the nation' s sexiest female buttocks will be held on November, 6 in Sao Paulo. (Photo by Nelson Almeida/AFP Photo)

Yuan Zi, a male giant panda and Huan Huan, a female giant panda, share their life inside their enclosure at Zoo Parc De Beauval on January 25, 2012 in Beauval, France. A pair of giant pandas which have been loaned to the zoo by China, where they hope the pair will reproduce and help boost the world's dwindling panda population. (Photo by Franck Prevel/Getty Images)

Pakistani female police commandos attend a training session in Nowshera, near Peshawar Pakistan, Wednesday, February 11, 2015. Authorities formed a Special Combat Unit after Taliban militants stormed a Peshawar school on Dec. 16, 2014 and massacred 150 children and teachers. (Photo by Mohammad Sajjad/AP Photo)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)

Palestinian female Hamas security officers demonstrate their skills during a graduation ceremony in the northern Gaza Strip, Wednesday, April 2, 2014. 1200 officers graduated from advanced training courses that lasted one year in Gaza police academy of Hamas. (Photo by Adel Hana/AP Photo)

Russian Police academy female cadets march during a rehearsal for the Victory Day military parade at Dvortsovaya (Palace) Square in St Petersburg, Russia, Wednesday, May 7, 2014. Victory Day, marking the defeat of Nazi Germany, is Russia's most important secular holiday celebrated on May 9. (Photo by Dmitry Lovetsky/AP Photo)