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  Killed by Gavrilo Princip
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  Assassinating Franz Ferdinand kick started the war.
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  torpedoed without warning by a German submarine off the south coast of Ireland.
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  also known as the Somme Offensive,
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  Draft for the war
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  Shortly after the U.S. entry into World War I.
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  flu pandemic was an unusually deadly influenza pandemic, the first of the two pandemics involving H1N1 influenza virus.
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  Statement of principles for peace t
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  The Treaty of Brest-Litovsk
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  driven by the spectacular success of the German U-boat submarines and their attacks on Allied and neutral ships at sea,
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  against the Japanese Empire, Nazi Germany declared war against the United States,
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  To cover a broader range of offenses,