QUIZ: You knew it in school. How many of the 100 historical dates will you get right today?

The article discusses significant historical events and figures, including the discovery of Pluto by Clyde Tombaugh in 1930 and the impact of the 2006 reclassification of Pluto as a dwarf planet. It also touches on cultural references from the 1990s in the Czech Republic and the legacy of Harry Houdini's death. Additionally, it highlights President Petr Pavel's views on Russia and the Hungarian Revolution of 1956, which prompted military readiness in Czechoslovakia.