Answer: The memory of the last last thing the alchemist told him was triggered
Explanation: I don't understand the question
The topic sentence of paragraph 7 of the passage is That was in 1998, and by 2013, around 70,000 volunteers had removed more than 7.5 million pounds of garbage from along the Mississippi and other rivers in several states.
<h3>What do you understand by Topic sentence?</h3>
A topic sentence is a sentence that sums up the fundamental thought of a passage.
It is generally the main sentence in a passage. Otherwise called the fundamental thought what the author's situation on that theme, it exemplifies or sorts out a whole passage.
A theme sentence, generally the principal sentence in a section, presents the primary thought of that passage and establishes its vibe.
A theme sentence is particularly significant in articles, where points change from one passage to another. This makes knowing how to compose a subject sentence vital for any understudy or author.
For more information about topic sentence, refer the following link:
brainly.com/question/1771002
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