Why do the rules for marking stress and intonation keep changing? Don't we have any fixed rules?

With this 3 questions ! really need them right! 1. the first continental congress met in philadelphia on september 5, 1774. all of the colonies sent representatives except georgia. this congress continued in session until october 26, 1774. by then it had passed resolutions calling for a boycott against british trade. the author's main purpose was a. to inform b. to persuade c. to instruct d. to give an opinion 2. identify the point of view of each of the following passages. "my second mate was a round-cheeked, silent young man, grave beyond his years, i thought; but as our eyes happened to meet i detected a slight quiver on his lips. i looked down at once. it was not my part to encourage sneering on board my ship. it must be said, too, that i knew very little of my officers." (joseph conrad, "the secret sharer") a. first person b. third person limited c. third person omniscient d. none of the above 3. identify the point of view of each of the following passages. "he had only himself to in his choice: his fortune was his own; for as to frank, it was more than being tacitly brought up as his uncle's heir, it had become so avowed an adoption as to have him assume the name of churchill on coming of age. it was most unlikely, therefore, that he should ever want his father's assistance. his father had no apprehension of it." (jane austen, emma) a. third person omniscient b. third person limited c. first person d. none of the above