A horse pulls a driving school car as other drivers push their vehicles behind during a demonstration by driving instructors in Belgrade, September 25, 1992. Due to gasoline shortage in the Yugoslav capital, driving instructors are staying away from work. (Photo by AP Photo)

A Carlsbad,Calif. police officer turns traffic away as flames leap behind him Wednesday, May 14, 2014, in Carlsbad, Calif. Weather conditions that at least temporarily calmed allowed firefighters to gain ground early Wednesday on a pair of wildfires that forced thousands of residents to leave their homes. (Photo by AP Photo)

A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

People follow king penguins exploring their outdoor pen, during a so-called “penguin parade”, when the animals walk outside their enclosure and the visitors can walk behind them, at Zurich's Zoo in Zurich, Switzerland January 28, 2017. (Photo by Arnd Wiegmann/Reuters)

A traffic policeman hides a rose behind his back before giving it to a female driver ahead of International Women's Day in Ryazan, Russia on March 7, 2017. (Photo by Alexander Ryumin/TASS via Getty Images)

White House Communications Director and presidential advisor Hope Hicks arrives at the U.S. Capitol Visitors Center February 27, 2018 in Washington, DC. Hicks is scheduled to testify behind closed doors to the House Intelligence Committee in its ongoing investigation into Russia's interference in the 2016 election. (Photo by Chip Somodevilla/Getty Images)

Majesty Davis, 3, cries while visiting Santa Claus, who sits behind a plexiglass divider due to the coronavirus disease (COVID-19) pandemic, at the Willow Grove Park Mall in Willow Grove, Pennsylvania, U.S. November 14, 2020. (Photo by Mark Makela/Reuters)

A man walks behind camels at the Birqash Camel Market, ahead of Eid al-Adha or Festival of Sacrifice, on the outskirts of Cairo September 29, 2014. Birqash Camel Market, one of the biggest markets for camel meat in Africa, draws sellers from Libya, Sudan, Somalia and other regions in Egypt. The camels sold at the market are also used in tourism. Traders say that the selling rate for a camel in 2014 is anywhere between 5,000 and 20,000 Egyptian pounds (700 – 2800 USD). (Photo by Amr Abdallah Dalsh/Reuters)