What makes 20th century modern poetry "difficult" and what are some different types of difficulty?

What exaggeration about him smiley does the narrator of the notorious jumping frog of calveras county make

Who dies in a duel because of his pride and his anger

Part 7: the strange case of dr. jekyll and mahyuer commeresolutionpre-testactivea resolution isa struggle between opposing forcesa difficult event or situationthe message of a storythe end of a storysave and exit