How did US actions in Cambodia during the Vietnam War lead to the Khmer Rouge taking over the country?

Which is the best example of a primary source ducument useful in the study of history ?

If biblio is a word root meaning "book,” and phil means "love,” what is the best definition of bibliophile in the sentence below? elena was a bibliophile, so she amassed a library of thousands of books over the course of her life. someone who writes books someone who adores books someone who reads a lot of books someone who knows a lot about books

Following archduke franz ferdinand's assassination, austro-hungarian leaders: a. aided the ottoman empire in its campaign to keep serbia under its control. b. executed nearly all prominent serbs living in austria-hungary c. threatened to invade serbia if serb leaders did not agree to a set of strict demands. d.. formed an alliance with great britain to protect austria-hungary from future attacks.