A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

German flying ace Baron Manfred von Richthofen (1892–1918) also known as The Red Baron with his dog Moritz, circa 1916.

School leavers celebrate their graduation in Moscow's Red Square in Moscow, Russia on June 20, 2019. (Photo by Artyom Geodakyan/TASS)

A man stands by an installation depicting “2019” in the Red Square in Moscow, Russia on December 17, 2018. (Photo by Maxim Shemetov/Reuters)

Sеxy woman in lace eye cover and red lips with young lover, foreplay in hotel room. (Photo by sakkmesterke/Getty Images)

Russian soldiers dressed in Red Army World War II uniforms attend a rehearsal for the Nov. 7 parade in the Red Square with Spassky Tower in the background, in Moscow, Russia, Friday, November 6, 2015. The parade marks the 74th anniversary of a November 7 parade on Red Square when soldiers went directly to the front during World War II. For decades Nov. 7 was a holiday celebrating the 1917 Bolshevik Revolution. (Photo by Ivan Sekretarev/AP Photo)