I WILL GIVE BRIANLIST!! ASAP Which major event of the Middle Ages - the Crusades, spread of the Black Death, or the rise of nation states - created the greatest change in Europe, &
why? EXPLAIN WITH FULL SENTENCES

The Black Death

Explanation:

The Black Death bascially destroyed Europe, being a fatal disease.  The reason why it was so deadly though was because of how fast it spread.  Animals like rats first got the disease, then it spread to humans.  The diease spread so quickly was because  back then the towns were dirty and crowded, which rats often lived in, which caused rats to make common contact with humans.  

Hope this helps!  :)

four sitting presidents have been assassinated while in office but the first was abraham lincoln,

answer; /// i believe the correct answer is (oasis)