Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

The combination of Venezuela's sky-rocketing prices and chronic product shortages have left many struggling to put regular food on their tables and maintain a balanced diet. According to one recent study, 87 percent of Venezuelans say their income is now insufficient to purchase their food needs. Here: All the food available in the house of Antonia Torres and her family, is pictured at their home in Caracas, Venezuela April 22, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

Miss Australia 2014 Tegan Martin sits down with Miss Universe Chief Photo Editor Francis L. Szelwach to review her photos after posing in swimwear at the 63rd annual Miss Universe pageant in Miami, Florida, in this January 5, 2015 handout photo provided by the Miss Universe Organization. (Photo by Reuters/Miss Universe Organization)

Alfred Hitchcock (1899 – 1980) in front of a caricature of his profile at a press reception in London for his new film “Frenzy”. (Photo by Central Press/Getty Images). 24th May 1972

Egyptian President Hosni Mubarak speaks to the media after talks with German Chancellor Angela Merkel at the Chancellery on April 23, 2008 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

In this composite image Actress Sophie Marceau has an embarrassing moment as her top falls down while she enters a screening of “Where the Truth Lies” at the Grand Theatre during the 58th International Cannes Film Festival May 13, 2005 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)

The Villarica volcano erupts near Pucon, Chile, early Tuesday, March 3, 2015. The Villarica volcano erupted Tuesday around 3 a.m. local time (06:00 GMT), according to the National Emergency Office, which issued a red alert and ordered evacuations. (Photo by Aton Chile/AP Photo)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)