Please help need help #5

What is the “narrow cell” in line 15 of “elegy written in a country churchyard”

What is the meaning of "full tide" as it is used in this sentence? before i could explain to her the differences of language in this world, she was embarked on the full tide of another subject. a long and involved argument an inaccurate representation a detailed and lively discussion an uncontrollable flood

Awell-worded thesis statement is both and generally acceptable . . broad agreeable . . limited significant . . limited significant . . broa