27. in “a tragedy revealed: a heroine’s last days” the statement “anne frank, even in the most frightful extremity, was indomitable” means?

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