Why does rosaline represent a foil to juliet ?

Which number is main idea? i need . : 2. (1) stories of the mythical camelot, the location in england of king arthur’s court, depict a world of dashing knights in shining armor and beautiful damsels in distress. (2) in actuality, the real world of that time probably consisted of smelly men in rusty tin suits and damsels in a certain kind of distress—the distress of being constantly pregnant and of having no rights in a male-dominated society. (3) those same stories often glorified the brave men who fought to the death for king and country. (4) however, most battle fatalities of the time resulted from medieval medicine. (5) letting the “bad blood” out of a sick person was a common medical practice, and cleanliness was not. (6) other stories of the fabled camelot housed royalty in glittering palaces, clothed them in silks, and covered them in mystery and awe. (7) but what is awesome about living in a cold, stone, rat-infested fortress with poor ventilation? (8) as for silks, war-indebted kings could rarely afford such foreign commodities. (9) wool from home usually did the trick. (10) and there’s certainly nothing silky about the discomfort caused by coarse woolen undergarments. (11) it is obvious that the camelot myth ignores the harsh realities of life in the middle ages in favor of a fantastic, unrealistic view of history.