When is a semi colon necessary

Read the excerpt from black boy wright uses this personal experience to establish

He said it was because a private detective sees the dark side of human nature. but whatever the reason, gill landers had an innate suspicion of politicians. when senator randy brill walked into his office on that summer day in august, mopping his flushed features with a monogrammed handkerchief, gill could think of no good reason to change his attitude. he'd only met brill once. that had been two years ago at a country club reception for state political notables. since then, he'd learned all he wanted to know about the senator's sinister reputation. gill sat back in his chair, put his feet on his desk, and fought to keep a poker face. but there was no way he could stop the chill that coursed along his spine like a rush of ice water. 29. in this paragraph, the word notables probably signifies that the persons so described a. would like to be politicians. b. are wealthy people. c. have political influence. d. are contributors to charity.

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