Romania and Bulgaria signed the European Union’s Treaty of Accession, the last step to joining the Union.
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Francis Crick & James Watson's discovery of the double-helix structure of DNA was formally announced.
The Discovery Space Shuttle deployed the Hubble Space Telescope into low-Earth orbit.
New York state became the first to require license plates on automobiles.
Bell Labs demonstrated the first practical silicon solar cell in New Jersey, US.
Germany banned the denial of Nazi genocide against Jewish people during the Holocaust.
